MSc Projects
Complete MSc project list for Physics and Astronomy
The complete list of MSc projects offered for 2024-25 has been split by research area and then by supervisor.
To get more information about the research groups in the Department, please look at the research pages.
Please find the complete list of MSc projects below:
- Astronomy and Cosmology
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These projects are ideally suited to students on the MSc Astronomy and MSc Cosmology, although you are welcome to speak to the project supervisor if you are studying another MSc course and you have sufficient relevant experience.
For further details, please speak to the project supervisor using the contact details on their profile page.
- Dr Christian Byrnes - Not Available for 24/25
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Primordial black holes as dark matter (Ref. CB1)
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The nature of dark matter remains unknown, but cannot be a standard model particle. They are normally assumed to be a new particle. However, they could also be primordial black holes (PBHs) which formed in the very early universe, before big bang nucleosynthesis took place. This scenario is observationally constrained by many methods including gravitational microlensing and gamma rays caused by Hawking evaporation of low mass black holes. One mass window still exists in which the constraints do not rule out the existence of enough PBHs to match the observed abundance of dark matter (or arguably more windows, e.g. relics if black holes do not decay to nothing but leave a relic).
The goal of this project is to study the observational constraints on this scenario and/or models of inflation which could cause the correct number of PBHs to form at the required mass scale. Analytical and numerical skills (e.g. Mathematica or Python, etc) are important for this project. I would strongly recommend any student taking this project to take the cosmology, GR and advanced cosmology modules (all of which are core for the Cosmology MSc).
For a general (GR free) introduction to the basics of inflation I recommend the “Introduction to Cosmology” textbook by Barbara Ryden. This is the main recommended resource for the Cosmology module.
For a more specialist and advanced review article of this topic see https://arxiv.org/abs/2007.10722 . I have also written lecture notes here https://arxiv.org/abs/2112.05716 but only the second part is sure to be relevant, perhaps not the first part about inflation.
- Inflation and the hot big bang (Ref. CB2)
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Inflation is widely believed to have taken place extremely early during the history of the universe. Apart from providing a potential solution to the horizon and flatness problems (studied in the Cosmology module) inflation can also explain the origin of the primordial curvature perturbation (studied in the Advanced Cosmology module). Despite the widespread view that inflation is a successful theory, most details of inflation remain unknown. In particular, it is not known whether inflation was caused by a single field or multiple fields, and it is also unknown how the inflaton(s) decayed and reheated the universe after inflation ended. We just know that reheating must complete before the atomic elements formed during the process known as big bang nucleosynthesis.
The goal of this project is to study a specific scenario of two field inflation called the curvaton scenario and to see how the reheating process is an integral part of the success (or failure) of the curvaton scenario. In this scenario the inflaton field causes the universe to inflate while the curvaton field is subdominant (in terms of energy density) during inflation, but it generates the primordial curvature perturbation instead.
This will be a very theoretical project requiring strong analytical skills and also some numerical skills, for which Mathematica could be an ideal programme to use given its ability to manipulate analytic equations. You will have to do a lot of studying from journal articles since the main topic of this project is not included in textbooks.
I would expect any student taking this project to take the cosmology and advanced cosmology modules. QFT is also a recommended module but not essential.
For a general (GR free) introduction to the basics of inflation I recommend the “Introduction to Cosmology” textbook by Barbara Ryden. This is the main recommended resource for the Cosmology module.
An advanced textbook is called The Primordial Density Perturbation: Cosmology, Inflation and the Origin of Structure by Lyth and Liddle
NB: there is a very similar book called Cosmological inflation and large-scale structure by Liddle and Lyth, look at this one if it is easier to find. https://www.amazon.co.uk/Primordial-Density-Perturbation-Cosmology-Inflation/dp/052182849XFor a paper about the curvaton scenario see https://arxiv.org/abs/1403.4591 and for a more detailed study of reheating (of the inflaton and curvaton decay process, and how these can be connected) see https://arxiv.org/pdf/1608.02162.pdf.
- Prof Ilian Iliev - Not Available for 24/25
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Observational signatures of Cosmic Reionization (Ref. II1)
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After the hot Big Bang the Universe expanded and cooled, eventually turning the primordial soup of particles into a sea of neutral gas, starting the cosmic "Dark Ages". The light produced by the First Stars gradually ionized the universe again and ended the Dark Ages. This transition, called Cosmic Reionization had profound effects on the formation and character of the early cosmological structures and left deep impressions on subsequent galaxy and star formation. Within this project we will be analysing the results from state-of-the-art simulations of this process to infer the observable features produced by the first structures and detectable by the current generation of large dedicated observational facilities like the radio inferometer LOFAR.
- Properties of halos and large-scale structures (Ref. II2)
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The small density inhomogeneties left over from the period of fast initial expansion of the universe gradually grew under the force of gravity, and eventually formed the galaxies and large-scale structures we see today. Within this project we will be using the results from state-of-the-art numerical N-body simulations on supercomputers, some of which among the largest ever performed to date, to understand this process. In particular, we will study the non-linear evolution of structures - clustering, sub-structures and internal properties of galactic and cluster dark matter halos, redshift-space distortions and others. We will be comparing these features to data from large galaxy surveys in order to derive the fundamental parameters describing the universe we live in.
- Dr Raphael Kou
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Tomographic measurements of the growth of structures (RK1)
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It was discovered in the late 1990s that the expansion of the Universe was accelerating. Different concepts have been introduced to try to explain this observation and are referred to ‘dark energy’, which could be (for example) a new fluid or a sign of deviations from General Relativity. Dark energy does not impact only the expansion of the Universe but also the way structures grow. It is therefore possible to test theories by measuring the growth of structures as a function of redshift. The aim of this project is to perform such a tomographic analysis of the growth of structures using measurements of the Cosmic Microwave Background (CMB) gravitational lensing. This probe is sensitive to the matter distribution projected along the line-of-sight and can be combined with galaxy surveys which will make it possible to recover the dependance in redshift through the cross-correlation formalism. Available data include the CMB lensing map from Planck and the galaxies and quasars from BOSS/eBOSS. If there is time, it will be possible to compare the measurements to predictions from cosmological models, including the current standard model of cosmology. This project will require to use the python language in order to process data, model observations and estimate parameters.
- Dr Jon Loveday - Not Available for 24/25
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Spectroscopic classification in 4MOST (Ref. JL1)
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Spectroscopic classification in 4MOST The 4-metre Multi-Object Spectroscopic Telescope (4MOST; http://www.4most.eu/cms/) project will be carrying out a series of Galactic and extra-Galactic surveys. In this project you will implement machine learning algorithms in order to classify objects based on their simulated spectra. You will then run the trained algorithm on real spectra in order to both classify the source and to look for anomalies, such as spectra containing light from two overlapping sources.
- Preparing for 4MOST galaxy surveys (Ref. JL2)
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Testing the 4MOST observing strategy The 4-metre Multi-Object Spectroscopic Telescope (4MOST; https://www.4most.eu/cms/) project will be carrying out a series of Galactic and extra-Galactic surveys.
In this project you will analyse extra-Galactic survey target catalogues that have been run through the 4MOST facility simulator (4FS) that mimics the observing process, in which some targets will be missed or be otherwise unsuccessful.
You will then assess how well the statistics of the target catalogue, such as galaxy luminosity functions, stellar mass functions, and correlation functions, can be recovered from the simulated observations. Such work is vital to verifying the observing strategy and selection functions for the 4MOST project.
- Prof Antony Lewis
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Parameterizations of cosmological reionization for CMB predictions (Ref. AL1)
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It is know that the Universe reionized (became ionized again) at redshifts less than about 6. This leads to a distinct signature in the Cosmic Microwave Background (CMB) polarization due to scattering with CMB photons, which can be well measured with future observations. However the redshift evolution of the reionization process is rather unclear; there are currently a variety of mostly fairly weak constraints that still allow some freedom in how reionization progressed, and numerical simulation results also vary. The idea of this project is to develop simple parameterizations that can be consistent with the constraints, to allow reliable prediction for the CMB polarization signal using a simple model that is more physically motivated that those currently used at present. This will involve numerical work with python, and modifying our numerical Boltzmann code CAMB written in Python and fortran. You will collect various data constraints on the reionization signal, and try to develop simple 1-3 parameter models that can fit the data as well as being broadly consistent with the possibilities allowed by simulations. Predictions for the CMB will be calculated using CAMB, and numerical results calculated for the polarization to test the relevant parameters for the purpose of predicting the signal in future CMB observations. If there is time, you could look at parameter forecast constraints combining CMB data and the low-redshift data.
- Dr Eva-Maria Mueller - Not Available for 24/25
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Forecasting Cosmological Parameters for Next-Generation Galaxy Surveys: Probing Neutrino Mass and Primordial Non-Gaussianity (Ref. EM1)
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Project Overview: Cosmology, the study of the large-scale structure and evolution of the universe, has witnessed tremendous advancements in recent years. The next frontier in our quest to understand the cosmos lies in the deployment of next-generation galaxy surveys. These surveys promise to unveil the mysteries of the universe by providing unprecedented precision in measuring cosmological parameters. This project aims to play a pivotal role in shaping the design and scientific goals of these future surveys.
Project Objectives: The primary objectives of this project are as follows:
1. Cosmological Parameter Forecasting: Utilize advanced statistical and computational techniques to forecast cosmological parameters. Specifically, focus on the sum of neutrino masses and primordial non-Gaussianity.
2. Next-Generation Galaxy Surveys: Assess the potential of upcoming galaxy surveys in constraining these key cosmological parameters.
3. Survey Design and Optimization: Provide valuable insights to optimize the survey design, observation strategies, and data analysis techniques for forthcoming cosmological missions.
Research Focus:
1. Neutrino Mass: Neutrinos, being elusive and abundant, have a profound influence on the large-scale structure of the universe. Investigate how accurately next-generation surveys can measure the sum of neutrino masses. Explore the implications of these measurements for our understanding of neutrino properties and their role in cosmic structure formation.
2. Primordial Non-Gaussianity: Examine the impact of primordial non-Gaussianity on the cosmic microwave background, galaxy clustering, and large-scale structure. Develop forecasting techniques to quantify the constraints that future surveys can place on non-Gaussianity parameters.
Methodology:
1. Data Simulation: Generate mock datasets mimicking the expected observations from next-generation galaxy surveys, incorporating realistic noise and systematic effects.
2. Statistical Analysis: Apply Bayesian statistical methods to infer cosmological parameters from the simulated data. Employ Markov Chain Monte Carlo (MCMC) and machine learning algorithms for parameter estimation.
3. Survey Optimization: Collaborate with experts in survey design to suggest improvements and refinements based on the parameter forecasting results.
Expected Outcomes:
1. Precise Cosmological Constraints: Provide accurate forecasts for the sum of neutrino masses and primordial non-Gaussianity parameters, enhancing our understanding of fundamental physics and cosmology.
2. Survey Recommendations: Deliver recommendations for optimizing the design and execution of next-generation galaxy surveys to maximize their scientific output.
3. Scientific Impact: Contribute to the advancement of cosmology by aiding in the development of a robust observational program that addresses key cosmological questions. Significance: The results of this project will be instrumental in shaping the next generation of cosmological surveys.
By improving our understanding of neutrino properties and the nature of primordial non-Gaussianity, we will take significant steps toward unravelling the mysteries of the universe's structure and evolution. This research will have implications for both fundamental physics and our broader understanding of the cosmos.
- Prof Seb Oliver
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- The Herschel Multi-Tiered Extra-galactic Survey: HerMES (Ref. SO1)
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The formation of stars in the distant Universe is a process usually shrouded in dust. This dust obscures the light from young stars which is absorbed and re-emitted as far infrared or sub-millimetre radiation. This process is so significant that half of all the light received from distant galaxies today half is seen at these long wavelengths. Thus understanding obscured star formation is critical to understanding galaxy evolution and so far very challenging. The European Space Agency (ESA) recently conducted a major €1B mission, Herschel, to study obscured star formation. The largest project on Herschel is HerMES mapped ~400 sq. degrees of the sky and is led at Sussex by Prof. Oliver. This project has already discovered 100s of thousands of distant obscured galaxies (compared to about 2000 prior to Herschel). Your project would contribute to HerMES, either in theoretically modelling the populations of galaxies we find or observationally in processing and analysing the data from Herschel and others telescopes observing the Herschel galaxies.
- Prof Kathy Romer
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Clusters of galaxies as cosmological probes and astrophysical laboratories: making use of the latest X-ray and optical surveys (Ref. KR1)
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Clusters of galaxies offer a unique window on the universe. As the largest collapsed objects in the heavens, they can be used to probe cosmology in a variety of ways. Moreover, they are host to a range of complex astrophysical processes and hold the key to unlocking mysteries such as the evolution of galaxies. The X-ray Cluster Survey (XCS) is an international, Sussex led, project (~20 scientists) that has uncovered more X-ray bright clusters than any other survey before it. This world leading project is ripe for scientific exploitation, with thousands of clusters available for individual or ensemble analysis. The student would also be able to take part in the much larger (~500 scientists) Dark Energy Survey (DES) - an optical project aiming to detect up to 100 times more clusters than XCS using the signature of galaxy over density. MSc students in Romer's group have the opportunity to work on projects related to either XCS or DES (or both). Students with both a desire to go on to PhD student, and coding experience, are particularly welcome (if you have no coding background, start teaching yourself Python before you arrive).
- Prof David Seery
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Inflation (Ref. DS1)
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Our best picture of the early universe is the inflationary paradigm, in which the universe cooled and expanded rapidly. After inflation the universe is supposed to thermalize at some high temperature, setting the initial conditions for the hot big bang. Small quantum fluctuations generating during the inflationary epoch provide seeds for the cosmic microwave background anisotropy, and the distribution of large-scale structure.
A number of projects are possible in this general area, depending on your background and interests. We have a significant investment in both analytic and numerical methods. Examples could include:- Stochastic modelling of inflationary perturbations, including first-passage probabilities (currently a hot topic)
- Numerical computation of power spectrum (possibly beyond tree-level, also a hot topic, if you the right background)
- Reheating after inflation
Projects in this area are likely to be quite heavy on theory, and it will help if you already have some background (such as an undergraduate course on cosmology or general relativity). You should expect to take the Cosmology (Autumn Term) and Advanced Cosmology (Spring Term) modules offered as part of the MSc. We will also use the content of the General Relativity module (Autumn Term). QFT is recommended and will help you understand some of the material, but you can also self-study from a textbook.
Suggested reading:
Cosmology, Baumann, Cambridge University Press. This is the most recent cosmology textbook and a good choice if you are looking for something to supplement lectures. It is based on an MSc-level Cosmology course. It helpfully includes a lot of details for calculations that are usually suppressed. Chapters 3 and 4 give a good introduction to the current cosmological model, and inflation, respectively.
The Primordial Density Perturbation, Lyth & Liddle, Cambridge University Press. Chapters 4 and 5 give a good introduction to the current cosmological model, and Chapter 18 gives a good introduction to inflation. Be aware that there is an earlier version of this book called "Cosmological Inflation and Large Scale Structure" by Liddle & Lyth (note the different order of authors), so please don't get them confused.
- Prof Robert E. Smith
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Weak Gravitational Lensing in Cosmology (Ref. RS1)
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In this project we will explore how the technique of weak gravitational lensing can be used to study the mass distribution in the Universe. In particular we will look at the so called aperture mass statistics for testing the statistical properties of dark matter. In addition, we will look to build better theoretical predictions for the signal from the large-scale cosmic structures.
- Prof Stephen Wilkins
- Exploring the formation and evolution of galaxies with JWST (Ref. SW1)
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For more information on the project listed below, please use contact details listed on the supervisor's profile page.
Since its successful launch on Christmas Day 2021 the James Webb Space Telescope (JWST) has embarked on its mission help better understand galaxy formation and evolution across the history of the Universe. In this project you will analyse JWST observations to tackle various outstanding problems in galaxy evolution. Depending on the interests of the student, and existing work in this fast moving field, there are several different possibilities for projects. These include:
- measuring the morphologies of galaxies from deep imaging.
- developing a robust selection process to identify high-redshift (distant) star forming galaxies.
- directly comparing JWST images with synthetic images generated from galaxy formation models.
- measuring spectral features in JWST spectroscopy.
- exploring the impact of modelling assumptions on the recovered physical properties of galaxies.
- Atomic, Molecular and Optical Physics
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These projects are ideally suited to students on the MSc Physics and MSc Frontiers of Quantum Technology, although you are welcome to speak to the project supervisor if you are studying another MSc course and you have sufficient relevant experience.
For further details, please speak to the project supervisor using the contact details on their profile page.
- Prof Barry Garraway
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Decay of quantum systems (Ref. BG1)
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There are two choices of project here which look at issues in the topic of decoherence, or the decay of quantum systems. In the first project you will examine how a quantum system coupled to an environment can be understood as a system coupled to a chain of quantum oscillators. This has been of recent interest in understanding photosynthesis. The project will model a simple system using the chain and examine how excitation travels down the chain. In the second project a model will be made of a quantum system with three resonances, which poses interesting issues for simple representations and approximations to the system because of interferences.
- Control of cold atoms with electromagnetic gratings (Ref. BG2)
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Ultra-cold atoms and BECs have the potential to revolutionise the technology of, for example, interferometry, rotation sensing, and gravimetry. Improving this technology requires new kinds of atom traps which are under design and construction. This theory project will look at methods for ejecting atoms from their traps and in particular will examine the use of electromagnetic gratings (such as standing waves) for creating momentum distributions from the cold atoms (i.e. a beam splitter for atoms).
- Cold atoms in rf traps (Ref. BG3)
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In this project you will examine the behaviour of cold atoms in hybrid traps composed of magnetic and electromagnetic fields. Modelling of experiments may be undertaken. Double-well potentials leading to applications in matter wave interferometry are of particular interest. (Computing ability is essential.)
- Prof Winfried Hensinger
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
Ion Quantum Technology
Quantum theory can have powerful applications due to the possibility of implementing new quantum technologies such as the quantum computer. While such a device could have very important commercial and national security applications due to the existence of quantum factoring algorithms, its existence would revolutionize modern day science by allowing true quantum simulations of systems that may be modelled classically only insufficiently due to an in-principle limitation of current computer technology. Recent developments in ion trapping technology show that it should be possible to build a quantum computer with trapped ions. In the Ion Quantum Technology group at Sussex, we are in the process to build an elementary quantum computer, an effort that will be based in Sussex but include links to nanofabrication facilities, ion trapping groups and theorists around the world. (More information, including a virtual lab tour, can be found at: http://www.sussex.ac.uk/physics/iqt/)
- Cooling of ytterbium ions using lasers and microwaves (Ref. WH1)
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Trapping single atoms is being described as one of the most demanding experiments in atomic physics. This project includes experimental work in trapping and cooling single ions towards the realization of an ion trap quantum computer. This project includes both theoretical and experimental parts. You will learn about laser and microwave cooling of ytterbium ions. The IQT group has recently succeeded in cooling ions to the quantum mechanical ground state using microwaves, a world’s first. You will work on this experiment and investigate ways to further improve this method as well as extend it to more ions, a prerequisite for many experiments. You will also learn how to align lasers onto the ion trap, operate a laser locking scheme, and handle a complicated imaging system.
- Stabilising a ytterbium ion trap quantum computer setup (Ref. WH2)
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The IQT group is developing a quantum computer based on trapped ytterbium ions which requires a multitude of innovative components to be stabilised and protected from external noise. This includes special laser systems as well as high power microwave generation setups. As part of this project you will learn about relevant noise sources in the laboratory and investigate optimum methods to protect against it. You will also learn about lasers and microwave generation setups and how to best ‘actively’ stabilise these. To achieve this you will design, build and program highly efficient locking setups based on FPGAs which will form the basis of our quantum computing experiments which includes the efficient generation of high-fidelity entanglement and state detection.
- Advanced ion chips (Ref. WH3)
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For large scale quantum computing to occur large scale ion trap arrays need to be designed that allow optimal storage, shuttling and entanglement operations to be performed. The arrays are constructed within an integrated microchip. In this project you will study how to add advanced features to ion chips such as digital signal processing, on-chip cavities, fibre connects along with on-chip resistors and capacitors. In addition, you will devise recipes for the application of microwaves on the chip and the implementation of magnetic field gradients. You will identify important issues in nanofabrication of ion traps and address such challenges with advances in condensed matter physics.
- Shuttling trapped ions inside arrays (Ref. WH4)
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In our group we develop advanced ion trap arrays on a chip. In order to transport ions through such an array of electrodes the motion of the ion has to be carefully controlled. This project investigates how ions can be carefully shuttled in such an ion trap array without changing their motional quantum state. You will investigate optimal ways to transport individual ions and develop voltage sequences that are applied to multiple electrodes in order to move ions along a line, transport them through a junction or separate ions that are part of an ion string.
- Entanglement creation (Ref. WH5)
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Quantum technology, particularly quantum computing relies on the ability to entangle ions. Entanglement has been referred by Einstein as “spooky” and is one of the most counterintuitive predictions of quantum physics. At Sussex we have developed a scalable method to create entanglement using microwaves. This project may involve some theory, programming and experimental work. You will evaluate how to increase entanglement gate fidelities in order to reduce error rates within quantum computing operations.
- Quantum simulations with trapped ions (Ref. WH6)
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Richard Feynman pioneered the idea that instead of trying to simulate quantum systems with classical computers, it is much more efficient to use a quantum system that can be controlled in the lab to simulate another quantum system one would like to understand. There is a vast range of possible quantum simulations that can be performed using trapped ions from all areas of physics, including effects of Einstein’s theory of special relativity, the Kibble-Zurek mechanism, particle creation moments after the big bang and complex many-body phenomena such as quantum biology and quantum chemistry. The aim of this project is to analyse and further develop theoretical proposals for quantum simulations and carry out the corresponding experiments using trapped ions at Sussex.
- Developing a portable quantum sensor (Ref. WH7)
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Sensors form a major part of every-day technology and can even be found in modern day mobile phones. The applications are endless and a continuous effort is underway to improve their sensitivity. A quantum sensor makes use of the ‘strange’ effects of quantum mechanics to provide a step-change in the achievable sensitivity and is seen as one of the most promising quantum technologies to be commercialised in the near future. The IQT group is working on developing a portable ion-trap based magnetometer which can be used to sense magnetic fields with unparalleled sensitivity. Within this project you will familiarise yourself with how a quantum sensor works. In order to develop a portable quantum sensor, an experiment filling an entire lab needs to be reduced to the size of a shoe-box. You will learn about the core components making up our ion trap based magnetometer and develop ways to significantly reduce their size. This will include the development of miniaturised laser and vacuum systems.
- Communicating quantum technology (Ref. WH8)
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A famous quantum physicist once proclaimed that the only physicists who understand quantum physics are the ones who know that they don’t understand it. Within this project you will analyse the factors that lead to the difficulty in obtaining an intuitive understanding of quantum physics. Once these factors become clear, you will devise strategies to circumvent such problems and create a strategy to communicate quantum technology research to a number of different target groups such as the general public, A-level students and undergraduate physics students. You will then create appropriate materials such as websites, simulations, applets, handouts and hand-on demonstrations in order effectively communicate quantum technology research. You will also measure the efficiency of the created strategy and materials by analysing its effect on various target groups. Experience in making highly sophisticated websites and interactive simulations is critical.
- Dr Matthias Keller
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Ion trap for the quantum internet (Ref. MK1)
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In order to create a ‘modem’ for the quantum internet, single atomic ions must be coupled to an optical cavity. In my group we currently operate four ion traps to explore schemes to implement such a modem to transfer the quantum information from an ion to photons which carry the information through the network. In this project you will design, build and test a novel ion trap which is combined with an ultra-small optical fibre cavity. The project starts from the design and simulation of the trap and follows the trap development through to the actual implementation.
- Micro-controller based Signal Processing (Ref. MK2)
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Electronic circuits are indispensable in modern quantum technology. Often, the required processing of signals can’t be easily done with analogue electronics. Using fast analogue-to-digital converters together with a micro-controller can serve as a versatile signal processing unit. The signal is digitalised and processed by the programmable micro-controller and then converted back into an analogue signal.
The goal of this project is the programming of a PIC micro-controller to serve as a versatile signal processing system. It includes the design and test of peripheral electronic circuits. - Lasers for the quantum internet (Ref. MK3)
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Lasers are an indispensible tool to create the quantum version of the internet. They are required to cool, manipulate and prepare trapped ions in a specific quantum state (qubit state). Furthermore, lasers are needed for controlling the interaction of ions and photons to generate single photons or for long distance ion-photon entanglement, building blocks for the quantum internet. As a reference for all the lasers we build a ultra-high precision laser which is referenced to a state-of-the-art optical cavity. In this project, you will improve the performance of the laser and help to transfer its stability to other lasers in the lab. Furthermore, you will be working to implement these lasers in our quantum internet experiments.
- Testing the foundations of physics with lasers (Ref. MK4)
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The laws of physics, as we know them, require a set of fundamental constants. However, in recently years there are strong hints that these constants are actually changing in time. To measure this, we set up a system to perform ultra-high resolution spectroscopy on single molecules. For this we require unique lasers which allow us to prepare the molecules in a specific quantum state. In this project you will build a pulsed titanium:sapphire laser which a frequency conversion system to generate laser radiation in the far UV.
- Fibre cavities for the quantum internet (Ref. MK5)
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For our research to create a quantum version of the internet, ultra-small optical cavities are required. In the recent years, we have developed a unique system to fabricate these high performance cavities. In order to further improve the quality and reliability of our production process the re-design of a crucial component is required. In this project you will design, build and test a novel mounting structure for optical fibres for our fabrication system.
- Dr Fedja Orucevic
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Dynamics of trapped ions (Ref. FO1)
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The ability to confine atoms to a defined small region in space has led to many advances in science, especially in atomic physics. Today, a great variety of such traps exist and are routinely used in many laboratories around the world, investigating fundamental questions such as quantum non-equilibrium physics as well as applications such as new time standards in atomic clocks and in precision measurement of gravitational and electromagnetic fields.
In this project, we will study the dynamics of particles in externally shaped potentials, and theoretically determine the conditions under which the motion is predictable, stable and bounded, so that the potential forms a trap. Furthermore, we will explore when and how instabilities start to play a role at the onset of chaotic motion. Experimentally, we will design and build a simple trap by an appropriate combination of DC and AC charged electrodes. While this assembly will be capable of trapping individual atoms, we will test it with ionised micro-beads whose motion is easily observable with appropriate commercial optics, allowing us to compare experimental results to theoretical predictions. The balance between theory and experiment can be tailored to suit the interests of the students and to pursue the most promising discoveries made during the project.
- Mach-Zehnder interferometer and quantum eraser (Ref. FO2)
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We will study and understand basic optics with a focus on polarization of light and how it can be influenced by waveplates, polarisers and beam splitters. We will set up a Mach-Zehnder interferometer to create two indistinguishable paths along which light from a single source propagates. The contrast of the resulting interference pattern is reduced when the indistinguishability of the paths is lifted, i.e. when (partial) which-way-information becomes available by controlling the polarisation in the different beam paths. We will analyse this effect in detail and discuss its relation to the famous wave-particle duality in quantum physics. In this context, we will investigate also the quantum eraser effect by showing that the interference pattern will reappear if the gained information is erased by introducing a polariser after the two beams have been overlapped again. This experiment is related to fundamental physics, quantum optics, decoherence and the quantum-to-classical transition.
- Noise in cold atom imaging (Ref. FO3)
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Laser cooling can bring gases of atoms to temperatures of less than a millikelvin above absolute zero. In this project, you will investigate how clouds of about ten million rubidium atoms at these temperatures can be detected. The most common technique is absorption imaging: the cloud is exposed to monochromatic laser light tuned to a strong atomic resonance. By absorbing the light, the atomic cloud casts a shadow into the light beam, which is then detected on a CCD camera. Alternatively, the light re-emitted from the atoms (fluorescence) can be collected on a photodiode or a CCD chip. We will initially explore these two imaging techniques theoretically, in particular in view of questions of high practical relevance, e.g. the expected signal-to-noise ratio of the detection as a function of experimental and technical parameters, such as atomic density, light intensity, the quantum efficiency of the camera, optical properties of the lenses used etc. Based on these calculations and corresponding expectations for experimental outcomes, you will take a series of images in an existing experimental setup and interpret the obtained images in terms of their noise. In particular, the distinction between photonic noise and atomic noise will be relevant.
- Conveyor belt for quantum gas magnetometer (Ref. FO4)
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Recent rapid advances in the field of laser cooling and trapping with routine preparation of nanokelvin cold samples of quantum degenerate gases (Bose-Einstein condensates) have led to new concepts in quantum technologies, e.g. for computing, communication and metrology applications. In our research lab we are working on microscopic magnetic field sensors, whose record field sensitivity is reliant on the low temperature and the quantum properties of the gas.
An important component of the microscope apparatus is a mechanism to move the sensor probe (a trapped sample of Bose-condensed atoms) to very close (microns) proximity of the sample. This transport from the atom cooling region to the sample region over a few centimetres will be done magnetically. The goal of the project is to design and test a printed circuit board (PCB) that can produce the necessary time-varying magnetic fields. We will use ultrahigh vacuum (UHV) compatible multi-layer technology and will characterise the device during operation of our ultracold atom chip-based “conveyor belt”. The project involves magnetic field calculations, computer aided PCB design and experimental work on an existing ultracold atom setup.
- Acousto-optic modulator (Ref. FO5)
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Mixing acoustic waves with light has wide applications ranging from laser printers to atomic physics experiments. In this project, you will study a key acousto-optic device, the acousto-optic modulator (AOM). A transparent crystal is simultaneously exposed to orthogonally propagating sound and laser waves, such that the laser light is diffracted. You will observe and interpret the diffraction pattern and see how controlling the parameters of the sound wave changes it. In interferometric measurements (beating) you will determine the frequency shifts induced by the AOM. This project is mainly experimental, but will include some theoretical aspects as well.
- Lasers in modern atomic physics (Ref. FO6)
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Lasers are essential tools in atomic physics experiments, as their intrinsic coherence and small linewidths allow for a very precise control and manipulation of atoms. In a typical “cold atoms” experiment the lasers are used to perform a variety of tasks: cool the atoms by 6 orders of magnitude in temperature (down to few microkelvins), manipulate internal states of atoms (optical pumping), characterise atomic ensembles (fluorescence and absorption imaging), etc…
In this project we propose to integrate a new laser line into our cold atoms experiment. Successful implementation and characterisation of a laser will allow the student to put into practice and expand their knowledge in many areas of physics: quantum physics, optics, electromagnetism, electronics and feedback theory, programming and simulation.
Furthermore, by operating the laser in a real cold atom experiment the student will have the opportunity to get acquainted with many aspects of modern atomic physics, such as laser cooling and Bose-Einstein condensation.
- Magnetic traps for ultracold atoms (Ref. FO7)
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Using tunable narrow-band laser sources atomic gases can be cooled to microkelvin temperatures. The corresponding thermal energies are sufficiently small to be comparable to magnetic Zeeman shifts induced by magnetic fields on the order of the Earth’s field. In this project we will explore how microscopic traps for cold atoms can be formed by passing currents through patterned conductors on microchips. We will start out with simple two-dimensional geometries and static fields and move on to higher complexity involving oscillating currents in the radio and microwave frequency range (MHz to GHz) and three-dimensional layouts. Such magnetic (micro)traps are used to store atoms for further cooling beyond the capability of lasers as well as for experiments and technological applications of quantum physics.
- Prof Jacob Dunningham
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Secure quantum remote sensing and communication (Ref. JD1)
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Quantum sensing and quantum communications are two exciting new technologies that each offer capabilities beyond the scope of classical physics. Recently these two ideas have been brought together in a scheme for making remote measurements in a completely secure way [1]. This has many potential uses where the client cannot be co-located with the object being measured and needs to ensure that no information can be gained by an eavesdropper (or anyone who finds the measurement device). These might include monitoring a nuclear reactor, the performance of a vehicle, or the health of a person in the field, for example. A simple proof of principle has been demonstrated and the aim of this theory project is to extend this towards realistic applications. Instead of using entangled photons, we will make use of single photon sources, which will improve the efficiency, flux rates and robustness to noise effects. We will incorporate the idea of observed Fisher information as an accurate real-time diagnostic of errors and external influences. We will also carry out a security analysis for different attacks and show how the scheme can be extended to give substantial gains in precision through quantum enhancement. If there is time, we will investigate how this scheme can be adapted to implement direct secure quantum communication (DSQC) where a message can be sent completely securely without having to first establish a shared key. Current DSQC schemes suffer from a lack of authentication methods and are vulnerable to so-called photon-number-splitting attacks where an eavesdropper can skim off photons to gain information [2]. We will show how our scheme is hard-wired to be secure to these issues, giving it a real advantage in quantum communications.
[1] Peng Yin et al., Phys. Rev. Appl. 14, 014065 (2020)
[2] Youn-Chang Jeong et al., Entropy 22, 1268 (2020)
- Quantum-enhanced sensing devices (Ref. JD2)
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One of the most exciting new potential technologies to emerge from quantum physics is the ability to measure physical phenomena with unprecedented precision. This could allow us to subject scientific theories to higher levels of scrutiny and lead to a range of new industrial applications. Current sensors rely on conventional (classical) physics. However, by using a fully quantum approach it is possible to achieve much greater sensitivities to phenomena such as magnetic, electric, or gravitational fields or rotations. Quantum sensing could therefore be applied to detecting and identifying remote objects or (in the case of rotations) improving the precision of gyroscopes for navigation and stabilisation devices. This theory project will investigate new schemes for quantum-enhanced sensing, focussing especially on the use of Fisher information. This is an incredibly useful tool for quantifying the precision that can be achieved and often enables us to come up with surprising and powerful measurement schemes. We will consider quantum sensors both individually and as part of networks. It is known that classically-connected arrays of sensors, such as interconnected telescopes, can greatly improve measurement resolution. Quantum sensors have the added possibility of being able to be connected via quantum correlations and this project will investigate the advantages this additional functionality brings..
- Dr Jose Verdu Galiana
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
Development of Quantum Microwave Microscope
Background: The aim of this ambitious project is the development of a pioneering quantum microwave microscope using a single electron captured in a chip ion trap as the quantum microwave sensor/emitter. An electron in a trap is known as a geonium atom, an artificial quantum object with properties designed and manipulated by the experimenter with great control. The trapped electron has demonstrated as an outstanding system for testing the laws of physics with extremely high accuracy. In the geonium chip laboratory at Sussex (www.geoniumchip.org) we are developing a novel chip ion trap, which will make use of a trapped electron as quantum transducer of microwave radiation. The electron is the most accurate and sensitive detector and emitter of microwave fields, with ultimate single photon sensitivity. This allows for implementing the most advanced quantum metrology techniques for testing and measuring systems (for instance human tissue or materials) with microwave radiation, using entanglement and other quantum resources. Many applications can be envisaged with such an ultra-sensitive quantum sensor/emitter of microwaves. In our lab, we aim at developing a revolutionary microscope, operating in the microwave domain, with the geonium atom technology. This might allow for surpassing the current sensitivity limitations of microwave microscopes, enabling unprecedented observation possibilities of natural or man made systems. Several experimental projects are offered. The details of the project will be discussed with the students depending on their interests. Relevant technologies that will be used include, superconductivity, RF electronics, Microwave Engineering, Cryogenics, magnetic field design and measurements, chip design and simulation, and others. Excellent candidates might be offered a fully funded PhD position after the successful completion of the project.
Transferable Skills: Lab Skills, circuit design, Microwave Engineering, Superconductivity, RF-Electronics, Lab-View, data analysis, cryogenics, vacuum techniques, FFT analysis, Vector Network Analysis, chip design and simulation, team work (with people inside and outside Sussex).
References:
[1] J. Verdu, New J. Phys. 13, 113029 (2011)
[2] A. Cridland et al, Photonics 3, 59 (2016)
[3] M. Lanzagorta, Quantum Radar, Morgan and Claypool (2011)
- Magnetic field Stabilisation (Ref. JVG1)
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This experimental project aims at developing a superconducting shield for eliminating any externally induced magnetic field fluctuations in the trapping region. The stability of the magnetic field is critical for a good characterisation of the trapped particles and for the operation of the geonium chip as a microwave photon sensor/emitter for quantum microwave microscope and quantum radar applications. In this project the student will design, simulate, fabricate and measure closed-loop superconducting structures using YBCO or NbTi. These structures will be measured using a Hall sensor and a liquid nitrogen or liquid He cryostat.
- Detection of one trapped electron (Ref. JVG2)
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This experimental project will focus on optimising the cryogenic detection system employed for observing one single trapped electron for the Quantum Microwave Microscope / Quantum Radar. The detection system essentially consists of one superconducting helical resonator and a cryogenic amplifier made with discreet components (pHEMT FET transistors). The project will focus on the measurement and characterisation of the different types of available GaAs transistors capable of operating at cryogenic temperatures. After the characterisation of the transistors a low noise cryogenic amplifier will be implemented and measured using a vector network analyser. The project involves the use of LabView, Mathematica, ADS software plus RF test and measurement equipment and 4K cryostats.
- Cooling the electron down to the quantum ground state (Ref. JVG3)
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This experimental project will focus on the development of a 80 mK cryo-cooling system capable of cooling the electron’s motion down to its quantum ground state. The 80 mK cryo-cooling system will operate an Adiabatic Demagnetisation Refrigerator which will be coupled to a closed-cycle Gifford-McMahon 4K cryo-cooler. The project will involve the design, fabrication and measurement of several components, such as thermalisation boards, noise filters, RF and MW attenuators, current leads, heat sinks and others, all necessary for achieving the extremely low temperature regime of 80 mK.
- Implementation of Microwave Quantum Illumination with trapped electrons (Ref. JVG4)
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This experimental project will focus on implementing the quantum illumination protocol using one electron as the sensor and emitter of entangled microwave radiation. This goal is critical for quantum microwave microscopy and quantum radar applications. This project is very ambitious and will only be offered to first-class candidates with the possibility to continue with a fully funded PhD position after the end of the MSc. The details of the project will be discussed with the candidate.
- Experimental Particle Physics
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These projects are ideally suited to students on the MSc Physics and MSc Particle Physics, although you are welcome to speak to the project supervisor if you are studying another MSc course and you have sufficient relevant experience.
For further details, please speak to the project supervisor using the contact details on their profile page.
- Dr Lily Asquith
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PLEASE NOTE DR ASQUITH IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 21/22
For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Neutrino Oscillation Measurements using Machine Learning (Ref. LA1)
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Restrictions: students on this project must be either already skilled in computer programming, or have a reasonable basic knowledge and eager to learn.
The NOvA neutrino experiment is taking data using a pair of detectors separated by 800 km. The Near Detector (ND) is positioned at Fermilab near Chicago, and is directly in the path of the NuMI neutrino beam at the same location. Neutrinos are detected by the ND via their interactions with protons in the scintillation medium, which is essentially baby oil. The neutrino beam then continues through 800km of the Earth’s crust to the Far Detector (FD) in Minnesota. During this journey, neutrinos have the opportunity to oscillate in flavour, and it is this oscillation that we are measuring in order to answer some fundamental and challenging questions about the universe: what are the neutrino masses and mixing angles? These are fundamental constants of the universe as far as we know, and measuring these is the most exciting area in particle physics today. You will be working with analysis code (C++ and python) within the friendly neutrino physics group at Sussex, and will aim to improve the neutrino energy measurement using machine learning methods.
- Prof Alessandro Cerri
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Super-accelerated Machine Learning (Ref. AC1)
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Machine Learning (ML) is one of the cutting-edge research tools employed in the processing and analysis of particle physics data. These often rely on ML, and provides developments with potential for interdisciplinary applications in fields such as computational genomics, medical imaging and financial markets.
ML is usually implemented in software and is often affected by lengthy processing times, however a new class of computer accelerators is emerging on the market. These are based on programmable electronics ("Field Programmable Gate Arrays" in particular): devices surpassing in many cases more widely known hardware accelerators (such as GPU coprocessors) and offering great advantages in terms of I/O speed.
The project aims at developing machine learning based big data processing on such accelerators, taking advantage of the experimental particle physics detector data, to tackle the complexity of identifying particles in the experimental particle physics detector, or implementing a measurement based on data from the ATLAS experiment. You will be working in collaboration with senior and junior research scientists, learning how to work with this new class of hardware accelerators and developing solutions to a particle physics data analysis or detector-related problem.
This project is suitable for students with a keen interest in big data, machine learning and computing. Familiarity with either Python or C/C++ programming will be needed. You will be learning advanced machine learning and big data techniques, sharpen your knowledge of electronics, forefront computing tools and techniques, as well as high speed digital electronic systems.
- Flavour Physics at the Large Hadron Collider (Ref. AC2)
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Precision measurements in known sectors of the Standard Model can pinpoint discrepancies with respect to its predictions, therefore producing indications of new physics phenomena. The Flavour sector is one of the richest well-modelled precision domains where these discrepancies are still to be fully explored. Thanks to the high luminosity provided by the LHC, the ATLAS experiment can achieve unprecedented precision in some of these measurements, which range from precision determinations of particle properties (product ion mechanisms, lifetimes etc.) to the search and identification of properties of new particles: the ATLAS heavy flavour group is in fact the one responsible for the very first new particle discovered at the LHC. The Sussex ATLAS group is currently involved in the search for the very rare disintegration of B mesons into two muons, as well as the measurement of the lifetime of Bs CP eigenstates. You will take a major role in one of the Sussex ATLAS group analysis activites, building on the experience of the existing analyses in the flavour sector and additional indirect searches for new physics.
This project requires familiarity with C/C++ software development, and could benefit from the knowledge of Python, ROOT and particle physics data analysis tools. You will be acquiring skills in data analysis, big data, particle physics knowledge as well as teamwork.
- Prof Antonella De Santo
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- New Physics Searches in Multileptonic Final States with the ATLAS Experiment at CERN's Large Hadron Collider (Ref. ADS1)
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The Large Hadron Collider (LHC) at the European Centre for Particle Physics (also known as CERN), near Geneva, Switzerland, smashes proton beams of unprecedented high energies, recreating conditions thought to have existed in our Universe shortly after the Big Bang. The ATLAS detector is one of the two multi-purpose experiments at the LHC. It can be used to search for a wide range well-motivated processes beyond the Standard Model (BSM). Examples of BSM searches at ATLAS include direct or indirect searches for dark matter, the search for new particles linked to established experimental anomalies, or the search for new heavy leptons which might explain why neutrino masses are so small. Many of these searches are conducted using collision events where multiple leptons are produced in the final state. Sussex has a major involvement in the search for BSM physics in multileptonic channels. For your project, which will be based on the analysis of ATLAS data (real or simulated), you will become involved with one of these searches and contribute to their development. You will become integrated within the Sussex ATLAS team and interact collaboratively on a regular basis with various group members, in person or remotely. In the first weeks of your project, you will need to acquire relevant computing skills and rapidly become familiar with relevant analysis tools (e.g., C++ programming and ROOT analysis framework). Adequate guidance will be provided. However, you will also be expected to work independently, devoting sufficient time to your project throughout the year. Good disposition towards teamwork will be essential.
Recommended resources for initial reading:
[1] ROOT homepage, https://root.cern.ch/
[2] ATLAS experiment public webpage, https://atlas.cern/
- Dr Elisabeth Falk
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Neutrinoless double beta decay with the SNO+ experiment (Ref. EF1)
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Can the neutrino, one of the least understood building blocks of matter, be its own antiparticle? The existence of an extremely rare form of radioactive decay called neutrinoless double beta decay would give the answer "yes". This in turn would help us understand why the universe is made up of matter and no anti-matter.
The SNO+ experiment is an exceedingly sensitive instrument located in a nickel mine 2 km underground in Canada. Its main scientific goal is to search for neutrinoless double beta decay in a particular radioactive isotope. A positive result would be a major scientific discovery.
The isotope will be dissolved in a liquid that emits light when electrically charged particles give up energy to it. One of the calibration systems will inject light from LEDs into the liquid in order to help determine the precision of the physics measurements. You will use simulated data and data from a preparatory data-taking phase to study and optimise aspects of the calibration and analysis of neutrinoless double beta decay data. There may also be opportunities to make laboratory measurements as part of the optimisation of the calibration system.
Programming skills will be required; experience with Linux/C++ is an advantage.
- Dr Clark Griffith
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For more information on the projects listed below, please use the details provided on the supervisor's profile page
- Electric field modelling of liquid argon neutrino detectors (Ref. CG1)
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Liquid argon based Time Projection Chamber (TPC) detectors are in use in many existing and planned neutrino detection experiments, and will likely play a crucial role in measuring CP violation in neutrino oscillations measured in the DUNE experiment. Neutrinos passing through the TPC are detected when they interact with the liquid argon, generating electrons or muons depending on the neutrino flavour. These charged particles in turn leave ionisation tracks as they move through the liquid argon, and due to the presence of an electric field across the detector, the ionisation charge drifts to a grid of collection wires that allow spatial and time reconstruction of the paths of the charged particles generated by the neutrinos. Accurately reconstructing the tracks of the particles relies on understanding the electric field distribution throughout the detector. This project will involve modelling the structure of the electric field in the DUNE single-phase far detector and will study how changes in design effect the field distributions and operation of the detector.
- The search for sterile neutrinos with the SBND detector (Ref. CG2)
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A number of experiments have shown anomalies in neutrino oscillation results, hinting at a possible additional neutrino state beyond the three present in the Standard Model. The Short Baseline Neutrino programme at Fermilab aims to settle the question of whether or not the anomalies are real or not, with a set of three large liquid argon TPC neutrino detectors: ICARUS, MicroBooNE, and the Short Baseline Near Detector (SBND). SBND is currently under construction and will soon enter its commissioning phase, where a wide variety of software analysis tools will be needed to help analyse the initial data and ensure that the newly operating detector is working as expected and so that the main physics data taking period can begin as soon as possible. A student on this project will help develop software analysis tools for SBND commissioning focusing on low energy event reconstruction and/or light detection.
- Towards a new neutrino detection principle using opaque scintillator (Ref. CG3)
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The dominant paradigm in neutrino detectors involving liquid scintillators has been to strive for high transparency, with light detectors arrayed around the edge of the detector volume. A new detector concept called LiquidO has recently been introduced where the scintillator is instead purposely made opaque, so that light is trapped near its generation point and collected by a grid of wavelength shifting fibres running through the volume of the detector. This concept has the potential for unprecedented particle identification capabilities and background rejection, that may be applied to both fundamental neutrino physics and applications such as medical imaging and nuclear reactor monitoring and non-proliferation. Sussex is involved in the construction of a small prototype LiquidO detector. A student on this project can be involved in laboratory studies of the properties of candidate opaque scintillators, design and construction of the prototype detector, and software development of tools for simulating and analysing the detector response.
- Prof Jeff Hartnell
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Prototyping a totally new type of particle detector in the lab (Ref. JH1)
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Prof Jeff Hartnell and team members at Sussex are the co-authors of a new and totally counter-intuitive idea to make particle detectors using opaque scintillators. These are light emitting materials that the light can’t escape from. There’s a reason no one has tried this before, at face value it sounds crazy! However, when you think more about it then it becomes apparent that opaque scintillators are a whole new way of thinking about particle detection. This opens up the prospect of using many new materials and detector configurations. We expect this new detector technique will have a wide range of future uses in fundamental particle physics and applications ranging from medical PET scanners to detecting radioactive “dirty” nuclear bombs.
Opacity can be achieved in two ways, through light scattering and/or absorption. Our approach relies on a very short scattering length and an intermediate absorption length, producing a scintillator that is milky and translucent in appearance. Photons from the scintillator undergo a random walk about their origin, giving rise to stochastic light confinement. To extract the light a lattice of wavelength-shifting (WLS) optical fibres runs through the scintillator. Many configurations of the fibre lattice are possible, and fibres can run in all three orthogonal directions or for example, in a cylindrical geometry. A particular advantage of utilising fibres to extract the light from an opaque scintillator is that the technology scales to large areas very effectively.
You will work as part of the team at Sussex to prototype a totally new design of detector. Using this detector you will take data using a radioactive source in a variety of positions to establish the performance: the number of photons detector per unit energy deposited, the spatial resolution and the timing resolution. This project will be tailored to match the experience each student brings.
- Dr Josh McFayden
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- FASER(2): Looking forward to new physics (Ref. JM1)
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FASER stands for “ForwArd Search ExpeRiment” and is one the newest experiments based at the Large Hadron Collider (LHC) at CERN. It is a novel experiment searching for exotic long-lived and weakly-interacting new particles. Such particles are excellent candidates to explain the existence of Dark Matter. If they exist, these exotic particles would be produced in collisions inside the ATLAS detector and detected nearly 500m away in FASER.
The Sussex Experimental Particle Physics group has had involvement in the construction and commissioning of the FASER detector that is now installed underground at CERN. FASER is expected take data during LHC Run 3 (2022-2024) and in this project you will start to look at the available data and the relevant simulations to understand the performance of the detector in preparation for extracting possible signs of new particles and understanding the background processes that might obscure the observation such new particles.
In addition, studies are underway to determine what the upgrade for FASER, known as FASER2, could look like for the next (high-luminosity) phase of running for the LHC (2027-2040). You will investigate different designs of FASER2 to determine what layouts and detector technologies will be required to get the best sensitivity to new particles, such as those which could explain Dark Matter.
Your work on this project will take place within the "Collider" group of Experimental Particle Physics. You will interact on a daily basis with faculty members, research staff and other students. No previous knowledge of particle physics is required: the exact scope of the project will be adapted to your skills. Previous experience with programming (python or C++) would be useful but if you are not already a proficient programmer, you will be able to acquire the relevant skills necessary to complete your project successfully. A good disposition towards teamwork is also essential.
- Understanding our existence and searching for new physics by measuring the Higgs boson and the top quark with ATLAS (Ref. JM2)
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Probing the Higgs boson, the most recently discovered fundamental particle, and one unlike anything else we’ve discovered so far, is a critical priority in the search for new physics at the Large Hadron Collider (LHC) at CERN. It is responsible for giving fundamental particles their mass and has the strongest interaction with the largest mass particles.
The top quark is the heaviest fundamental particle in the SM and therefore has the strongest coupling to the Higgs. This makes LHC collisions where a Higgs is produced with a top-quark pair (ttH) one of the most exciting places to test for signs of new physics. Not only that but the interplay between the strength of the Higgs interaction with the top quark and with itself is directly related to the stability of the Universe at a quantum level. It is therefore a vital piece in the understanding of our existence!
In this project you will investigate new ways to measure the strength of these interactions more precisely using data and simulations from the ATLAS Experiment. This will include performing statistical fits to optimise the measurements, using the fits to understand the largest systematic uncertainties and investigating how to reduce these uncertainties in order to make more precise measurements.
Your work on this project will take place within the "Collider" group of Experimental Particle Physics. You will interact on a daily basis with faculty members, research staff and other students. No previous knowledge of particle physics is required: the exact scope of the project will be adapted to your skills. Previous experience with programming (python or C++) would be useful but if you are not already a proficient programmer, you will be able to acquire the relevant skills necessary to complete your project successfully. A good disposition towards teamwork is also essential.
- Dr Fabrizio Salvatore
- BSM searches at the Large Hadron Collider (Ref. FS1)
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The Large Hadron Collider (LHC) at CERN, near Geneva, Switzerland, collides protons of unprecedented high energies, recreating conditions thought to have existed in our Universe shortly after the Big Bang. The ATLAS detector is one of the two multi-purpose experiments at the LHC, designed to unveil evidence for new phenomena beyond the Standard Model (BSM) of particle physics. Supersymmetry (SUSY) is one of the well-motivated BSM theories that could be realised in nature at LHC energies. SUSY could for example hold the key to explaining the nature of Dark Matter in our universe. The Sussex ATLAS group has a leading role in the search for supersymmetric signals in leptonic final states at ATLAS.
You will become integrated within the Sussex ATLAS group for the duration of your project, interacting collaboratively on a daily basis with faculty members, research staff and other students. You will perform a computer-based analysis of ATLAS data, including from simulations, with the aim to contribute to the search for SUSY signals at the LHC. The scope of the physics content of your project will be adapted to your pre-knowledge of particle physics. If you are not already a proficient programmer, you will be expected to acquire rapidly the computing skills (e.g. C++ programming and ROOT analysis framework) necessary to complete your project successfully. A good disposition towards teamwork is also essential. Final goals of the project will be discussed with the student, to adapt them to the programme.
- Performance studies of the ATLAS Inner Detector Trigger, also in view of the ATLAS Upgrade (Ref. FS2)
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The ATLAS experiment is one of the two general purpose experiments currently taking data at the Large Hadron Collider (LHC) at CERN. In parallel to the analysis of the data presently collected by the experiement, there is a growing interest in studying the performance of the ATLAS detector once the LHC luminosity (i.e. interaction rate) will be increased by at least an order of magnitude with respect to the current value. In particular, there is growing interest in studying the rate of events that the ATLAS detector can record ("trigger" rate).
The student will work in collaboration with other members of the ATLAS group at Sussex to look at trigger rates at different luminosities from the ATLAS experiement. The student will also look at possible strategies to improve these rates in an upgraded LHC environment.
When meeting with supervior(s) and the other members of the ATLAS team working on this project the student will be introduced to the software used for the project and will be given all necessary resources.
- Mark Sutton - High Performance Distributed Computing for QCD calculations at Next-to-next-to-leading order (Ref. MS1)
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Increasingly, complex computational projects are making use of massive parallelism, running on high performance farms or using cloud computing infrastructure. While different problems require solutions different int heir details, many can be addressed using the similar solutions. This project addresses one such problem in particle physics - that of the efficient calculation of precision calculation of cross sections using, transferable high performance computing solutions.
The large volume of precise data from the CERN Large Hadron Collider experiments demands precision theoretical calculations of cross section for many different physics processes, not only to perform the most stringent tests of the physics of the Standard Model, but also to facilitate the discovery of the first signs of any new physics beyond the standard model, such as SUSY or of Extra Dimensions.
Unitl recently calculations for LHC cross sections were available only at next-to-leading order (NLO) or perturbation theory. Over the last few years, new calculations at next-to-next-to-leading order (NNLO) have become available. These calculations are significantly more precise that NLO, but also significantly more complex, being both significantly more difficult to run, but also much more time consuming.
Typically such a calculation for a single physics process takes of the order of 100000 hours of CPU, and involves the running of many thousands of individual calculational fragments, all running independently, on different machines. With only a small number of machines, calculating the range of cross sections that are needed by the LHC experiments, even for the current data, would take a great many years. As such, methods such as multi-threading are used to accelerate the individual execution of the code, but more importantly it is essential to run the calculations with massive parallelism on high performance computing farms, or on the grid, or the cloud, and then combine the output from the many thousands of jobs upon completion.
Infrastructure to allow this mode of significant computational endeavour could in principle make use of existing tools common to many different large scale computational problems. This project will involve identifying any such industry standard tools that could be used or adapted for this specific problem and developing a framework for the submission of fragments of the full calculation on massively parallel systems and the collection and combination of the output upon job completion. The ultimate aim is to allow the results of calculations that might otherwise take many years to become available in the order of days.
The increasingly large number of measurements from the LHC experiments means that the demand for precision calculations for the many different processes is very high, such that results from the calculations run in this way will be used directly by the LHC experiements for many years to come.
Recommended resources:
http://en.wikipedia.org/wiki/distributed_computing
http://www.sussex.ac.uk/its/services/research/highperformance
http://en.wikipedia.org/wiki/Quantum_chromodynamics
- Dr Mark Sutton
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Determining the quark and gluon composition of the proton from LHC data (Ref. MS1)
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For the precise measurement of any proccess at the Large Hadron Collider at CERN, such as Higgs Boson production or for measurements sensitive to any potential signal from new, Beyond-the-Standard-Model processes such as SUSY, it is very important to have a a precise understanding of the quark and gluon content of the colliding protons.
To determine this, the approach is to perform QCD analyses of existing data from the LHC and other colliders, where the the predictions from state-of-the-art calculations of Standard Model processes are compared to the observed cross section data, with the quark and gluon distributions in the proton treated as free parameters. These are then varied to provide the most accurate prediction of the measured data.
New next-to-next-to-leading order (NNLO) QCD calculations for many processes, such as the production of W or Z bosons, Higgs production and QCD jet production have become available in the last few years, but at present the effects of these can only be included in the QCD fits as ratios with respet to cross section calculated at next-to-leading order (NLO).
This project is to work with people at Sussex on a project to use the full details of the NNLO calculations for LHC processes in the QCD analyses for the first time. It will involve running the state-of-the-art QCD calculations at NNLO in a high performance distributed computing environment, and then using the resulting predictions in a QCD analysis. This will result in one of the most precise determinations of the proton structure, and will result in a paper that is eagerly awaited by the entire particle physics community, and which will form an essential part of additional QCD analyses by other groups around the world who provide information on the structure of the proton. These distributions will in turn be used by all the particle physics experimental collaborations, including ATLAS and CMS, and by theorists working on the physics of proton-proton interactions.
Recommended resources
• https://en.wikipedia.org/wiki/Parton_(particle_physics)
• https://iopscience.iop.org/article/10.1088/0034-4885/42/8/001/pdf.
- High performance Distributed Computing for QCD calculations at Next-to-next-to-leading order (Ref. MS2)
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Increasingly, complex computational projects are making use of massive parallelism, running on high performance farms or using cloud computing infrastructure. While different problems require solutions different in their details, many can be addressed using the similar solutions. This project addresses one such problem in particle physics —that of the efficient running of precision QCD calculations using transferable high performance computing solutions. The large volume of precise data from the CERN Large Hadron Collider experiments demands precision theoretical calculations of the cross section for many different physics processes, not only to perform the most stringent tests of the physics of the Standard Model, but also to facilitate the discovery of the first signs of any new physics beyond the standard model, such as SUSY or of Extra Dimensions.
Until recently calculations for LHC cross sections were available only at next-to-leading order (NLO) or perturbation theory. Over the last few years, new calculations at next-to-next-to-leading order (NNLO) have become available. These calculations are significantly more precise than NLO, but also significantly more complex, being both significantly more difficult to run, bus also much more time consuming.
Typically such a calculation for a single physics process takes of the order of 100000 hours of CPU, and involves the running of many thousands of individual calculational fragments, all running independently, on different machines. With only a small number of machines, calculating the range of cross sections that are needed by the LHC experiments, even for the current data, would take a great many years. As such, methods such as multi threading are used to accelerate the individual execution of the code, but more importantly it is essential to run the calculations with massive parallelism on high performance computing farms, or on the grid, or the cloud, and then combine the output from the many thousands of jobs upon completion. Infrastructure to allow this mode of significant computational endeavour could in principle make use of existing tools common to many different large scale computational problems. This project will involve identifying any such industry standard tools that could be used or adapted for this specific problem and developing a framework for the submission of fragments of the full calculation on massively parallel systems and the collection and combination of the output upon job completion. The ultimate aim is to allow the results of calculations that might otherwise take many years to become available in the order of days.
The increasingly large number of measurements from the LHC experiments means that the demand for precision calculations for the many different processes is very high, such that results from the calculations run in this way will be used directly by the LHC experiments for many years to come.
Recommended resources
• https://en.wikipedia.org/wiki/Distributed_computing
• http://www.sussex.ac.uk/its/services/research/highperformance
• https://en.wikipedia.org/wiki/Quantum_chromodynamics .
- Theoretical Particle Physics
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These projects are ideally suited to students on the MSc Physics and MSc Particle Physics, although you are welcome to speak to the project supervisor if you are studying another MSc course and you have sufficient relevant experience.
For further details, please speak to the project supervisor using the contact details on their profile page.
- Prof Andrea Banfi
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Jet physics at the LHC (Ref. AB1)
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Hadronic jets, highly collimated bunches of energetic hadrons, are ubiquitous in today's particle physics. The student will learn Quantum Chromo-Dynamics (QCD), the theory underlying jet physics, and will be able to compute an observable involving jets, relevant either for precision studies or new physics searches at the LHC. During the project the student will also become familiar with various technical tools, like methods for numerical analyses, and programming in various languages (FORTRAN, C++, Perl, Python).
- Dr Manuel Reichert
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Quantum gravity scattering amplitudes (Ref. MR1)
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The project concerns the computation of scattering amplitudes with quantum gravity effects, for example, electron + positron -> graviton -> muon + anti-muon. These graviton-mediated amplitudes are crucial physical observable and relate to the important properties of the quantum theory such as causality and unitarity. As part of the project, you will become familiar with non-perturbative methods in quantum field theory, the functional renormalisation group, the computation of Feynman diagrams, and important quantum field theory concepts such as spectral functions.
- Quantum gravity implications for beyond the Standard Model physics (Ref. MR2)
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Not all low-energy theories are compatible with quantum gravity. Common terminology is that the landscape contains all theories that can be completed with quantum gravity at high energies and, conversely, theories that cannot be completed with quantum gravity live in the swampland. By demanding compatibility with quantum gravity, we can constrain the parameter space or even fully exclude extensions of the Standard Model. This concerns models that provide dark matter candidates, an explanation for the matter-antimatter asymmetry, or other beyond Standard Model phenomenology. As part of the project, you will become familiar with non-perturbative methods in quantum field theory, the functional renormalisation group, the computation of Feynman diagrams, and various aspects of beyond Standard Model physics.
- Gravitational waves from phase transitions in dark Standard Model extensions (Ref. MR3)
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The nature of dark matter and the dark side of the Standard Model is still unknown. It is feasible that this dark sector is much more complicated than commonly assumed. For example, it could contain an additional non-Abelian gauge symmetry, a dark QCD-like sector, and the dark matter candidate would then be a bound state of the dark strong force (e.g., a dark proton). If the dark sector undergoes a first-order phase transition in the early universe, it could be detected through a stochastic gravitational wave signal measured today. Computing the gravitational wave spectrum of a given dark matter model provides constraints on the parameter space of the model. As part of the project, you will become familiar with finite temperature computations in quantum field theory, the computation of bubble-nucleation rates, and numerical phyton tools.
- Prof Xavier Calmet
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Quantum Gravity and Quantum Field Theory (Ref. XC1)
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Projects are available at the interface of general relativity and quantum field theory. You might be studying applications to cosmology, dark matter, quantum gravitational corrections to black holes, gravitational waves, singularities, inflation etc using effective field theoretical methods. While the power of the effective theoretical approach to quantum gravity is its model independence, you could also consider how to match the effective action for quantum gravity to fundamental UV complete theories of quantum gravity such as string theory.
- The Physics of Fundamental constants (Ref. XC2)
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Projects are available at the interface of particle physics theory, atomic and molecular physics (AMO), cosmology and astrophysics. Fundamental constants of physics are usually assumed to be immutable. However, often models of physics beyond the standard model posit that fundamental constants could have a space or time dependence. For example, a time variation of the fine-structure constant or the proton mass could be generated by extremely light scalar dark matter, quintessence like fields posited to explain the cosmological constant, generic hidden sector fields, Kaluza-Klein states, dilaton fields, Brans Dicke fields, cosmic strings or domain walls.
You will learn about the theoretical framework behind these models and how to use tabletop experiments such as clocks and other quantum sensors to test physics beyond the standard model. This could include tests of grand unification or of quantum gravity. These are theoretical projects but with a close connection to experiments (https://qsnet.org.uk).
- Prof Stephan Huber
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Extra dimensions (Ref. SH1)
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It is possible that there are more than three space dimensions in nature. These extra dimensions could be responsible for observed properties of particles, e.g. their masses and couplings. In this project you will study a higher dimensional version of the Standard Model and investigate its consequences for particle colliders, such as the LHC.
- Electroweak symmetry breaking in the early universe (Ref. SH2)
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In the very early universe the electroweak symmetry of the Standard Model was unbroken, i.e. there was no Higgs field present. Extensions of the Standard Model predict that the breaking of this symmetry occurred via a first-order thermal phase transition (EWPT). This process could be the origin of the cosmic baryon asymmetry, and generate an observable signal of gravitational waves. You will study the properties of the EWPT (i.e. the jump in the Higgs field, the latent heat, etc.) in a model with extra Higgs fields, and derive consequences for particles physics and cosmology. This will be done by analysing the thermal potential of the Higgs fields. One aim is to test if the model is capable of generating the baryon asymmetry.
- Prof Sebastian Jaeger
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Techniques for multi-loop calculations in Quantum Field Theory (Ref. SJ1)
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Loop diagrams play an important role in quantum field theory both for conceptual and phenomenological questions. You will study some state-of-the-art techniqes such as integration by parts, sector decomposition, or the differential equation method and apply them to evaluating systems of Feynman integrals. The project requires both a high mathematical ability and a willingness to manipulate lengthy algebraic expressions.
- Prof Daniel Litim
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Quantum gravity in higher dimensions (Ref. DL1)
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Many particle theory models assume that the fundamental theory for gravity involves more than 4 dimensions. In this project, you explore higher-dimensional gravity and it's connections with the 4- dimensional theory using the renormalisation group.
- Infrared behaviour of gravity (Ref. DL2)
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In this project, you will explore the modifications to gravity as induced by long-distance quantum effects. You will develop a code to study renormalisation group equations for gravity. We want to understand whether infrared effects will lead to a modification of the gravitational force law.
- Phase transitions and the renormalisation group (Ref. DL3)
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Phase transitions in Nature are either continuous (second order) or discontinuous (first order). In this project, you apply the techniques of the renormalisation group to analyse first order phase transitions as relevant for eg. the QCD phase transition.
- Large-N limit in field theory (Ref. DL4)
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This project deals with the large-N limit in field theory, where N is the number of fields. We want to understand whether phase transitions and critical behaviour change in this particular limit, or not. As an application, we will look into the seminal Bardeen, Moshe and Bander phenomenon in 3d scalar theories, which we want to understand using modern renormalisation group technique.
- Black holes, quantum gravity and non-commutative geometry (Ref. DL5)
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This project aims at a comparison of salient features of black hole physics modified either by quantum gravity or by effects from non- commutative geometry. You will learn the basics of either set-up and evaluate similarities and differences of these two approaches when applied to black holes.
- Dr Nathaniel Sherrill
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Spacetime symmetry violations in particle physics (Ref. NS1)
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Fundamental symmetries and their violations are integral concepts in the modern understanding of particle and gravitational physics. Some theories beyond the Standard Model and General Relativity predict small violations from exact Lorentz and CPT symmetry that could be detectable in precision measurements. Projects are available to calculate QCD, electroweak, and lepton-sector Lorentz- and CPT-violating effects within effective field theory and to connect such effects to existing and future collider experiments.
- Dr Ennio Salvioni
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Dark matter through the Higgs portal (Ref. ES1)
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A new species of particles that was once in thermal equilibrium with the Standard Model is a compelling possibility to explain dark matter. Searches for such thermal dark matter are based on three strategies: direct detection, indirect detection, and collider experiments. Currently, the strongest constraints come from direct searches. This project will examine a theoretical dark matter scenario, where the Higgs field acts as a “portal” between dark and visible matter, that is naturally out of the reach of direct searches. Nevertheless, this scenario can be probed at colliders and in indirect detection experiments. The projected sensitivity of (proton- and muon-based) future colliders will be studied and compared to the reach of future indirect detection observatories, such as the Cherenkov Telescope Array. The project will require both analytical methods (quantum field theory calculations in the Standard Model and its extensions) and numerical techniques (use of Monte Carlo programs and associated data analysis).
- Dr Jonas Lindert
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Machine learning for dark matter searches at the LHC (Ref. JL1)
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The hunt for new particles including potential dark matter candidates is one of the prime goals of the Large Hadron Collider at CERN. In this regard machine learning techniques offer the possibility for significant sensitivity improvements discriminating new physics effects from overwhelming Standard Model background processes. This project will establish the physics principles of classifiers for jet/vector-boson/top-quark/Higgs-boson identification. Consequently based on machine learning techniques and an understanding of Quantum chromodynamics new classifiers will be developed and benchmarked using Monte Carlo simulations. As part of the project the student will become familiar with various computing tools, numerical methods, and programming in various languages (in particular C++, Python).
- Top-quark phenomenology (Ref. JL2)
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The top-quark as the heaviest known elementary particle allows for a unique view on the origin of electroweak symmetry breaking. At the same time it offers a plethora of production processes and signatures including different single-top production modes and production of up to four top-quarks at once. All these processes can be used to probe effects from New Physics interactions in complmentary ways. The project will explore different aspects of state-of-the-art top quark phenomenology. Depending on interest and previous knowledge the student will develop new precision simulations for top-quark processes including perturbative higher-order corrections and/or explore new analysis strategies. As part of the project the student will become familiar with various computing tools, Monte Carlo methods, and programming in various languages (in particular Fortran, C++, Python).
- Mathematical Physics
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For further details, please speak to the project supervisor using the contact details on their profile page
- Prof Xavier Calmet
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Project Econophysics (Ref. XC3)
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Option pricing is an important problem in mathematical finance. In this project you will learn about models to price options such as the Black Scholes or Merton Garman models and develop new mathematical techniques to solve the resulting partial differential equations. You will investigate the role of symmetries in option pricing models. Some background in mathematical finance is required for this project.
- Sussex Centre for Quantum Technologies
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These projects are ideally suited to students on the MSc Physics and MSc Frontiers of Quantum Technology, although you are welcome to speak to the project supervisor if you are studying another MSc course and you have sufficient relevant experience.
For further details, please speak to the project supervisor using the contact details on their profile page.
- Prof Barry Garraway
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Decay of quantum systems (Ref. BG1)
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There are two choices of project here which look at issues in the topic of decoherence, or the decay of quantum systems. In the first project you will examine how a quantum system coupled to an environment can be understood as a system coupled to a chain of quantum oscillators. This has been of recent interest in understanding photosynthesis. The project will model a simple system using the chain and examine how excitation travels down the chain. In the second project a model will be made of a quantum system with three resonances, which poses interesting issues for simple representations and approximations to the system because of interferences.
- Control of cold atoms with electromagnetic gratings (Ref. BG2)
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Ultra-cold atoms and BECs have the potential to revolutionise the technology of, for example, interferometry, rotation sensing, and gravimetry. Improving this technology requires new kinds of atom traps which are under design and construction. This theory project will look at methods for ejecting atoms from their traps and in particular will examine the use of electromagnetic gratings (such as standing waves) for creating momentum distributions from the cold atoms (i.e. a beam splitter for atoms).
- Cold atoms in rf traps (Ref. BG3)
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In this project you will examine the behaviour of cold atoms in hybrid traps composed of magnetic and electromagnetic fields. Modelling of experiments may be undertaken. Double-well potentials leading to applications in matter wave interferometry are of particular interest. (Computing ability is essential.)
- Prof Winfried Hensinger
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
Ion Quantum Technology
Quantum theory can have powerful applications due to the possibility of implementing new quantum technologies such as the quantum computer. While such a device could have very important commercial and national security applications due to the existence of quantum factoring algorithms, its existence would revolutionize modern day science by allowing true quantum simulations of systems that may be modelled classically only insufficiently due to an in-principle limitation of current computer technology. Recent developments in ion trapping technology show that it should be possible to build a quantum computer with trapped ions. In the Ion Quantum Technology group at Sussex, we are in the process to build an elementary quantum computer, an effort that will be based in Sussex but include links to nanofabrication facilities, ion trapping groups and theorists around the world. (More information, including a virtual lab tour, can be found at: style="font-family: 'Arial',sans-serif;">http://www.sussex.ac.uk/physics/iqt/
- Cooling of ytterbium ions using lasers and microwaves (Ref. WH1)
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Trapping single atoms is being described as one of the most demanding experiments in atomic physics. This project includes experimental work in trapping and cooling single ions towards the realization of an ion trap quantum computer. This project includes both theoretical and experimental parts. You will learn about laser and microwave cooling of ytterbium ions. The IQT group has recently succeeded in cooling ions to the quantum mechanical ground state using microwaves, a world’s first. You will work on this experiment and investigate ways to further improve this method as well as extend it to more ions, a prerequisite for many experiments. You will also learn how to align lasers onto the ion trap, operate a laser locking scheme, and handle a complicated imaging system.
- Stabilising a ytterbium ion trap quantum computer setup (Ref. WH2)
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The IQT group is developing a quantum computer based on trapped ytterbium ions which requires a multitude of innovative components to be stabilised and protected from external noise. This includes special laser systems as well as high power microwave generation setups. As part of this project you will learn about relevant noise sources in the laboratory and investigate optimum methods to protect against it. You will also learn about lasers and microwave generation setups and how to best ‘actively’ stabilise these. To achieve this you will design, build and program highly efficient locking setups based on FPGAs which will form the basis of our quantum computing experiments which includes the efficient generation of high-fidelity entanglement and state detection.
- Advanced ion chips (Ref. WH3)
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For large scale quantum computing to occur large scale ion trap arrays need to be designed that allow optimal storage, shuttling and entanglement operations to be performed. The arrays are constructed within an integrated microchip. In this project you will study how to add advanced features to ion chips such as digital signal processing, on-chip cavities, fibre connects along with on-chip resistors and capacitors. In addition, you will devise recipes for the application of microwaves on the chip and the implementation of magnetic field gradients. You will identify important issues in nanofabrication of ion traps and address such challenges with advances in condensed matter physics.
- Shuttling trapped ions inside arrays (Ref. WH4)
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In our group we develop advanced ion trap arrays on a chip. In order to transport ions through such an array of electrodes the motion of the ion has to be carefully controlled. This project investigates how ions can be carefully shuttled in such an ion trap array without changing their motional quantum state. You will investigate optimal ways to transport individual ions and develop voltage sequences that are applied to multiple electrodes in order to move ions along a line, transport them through a junction or separate ions that are part of an ion string.
- Entanglement creation (Ref. WH5)
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Quantum technology, particularly quantum computing relies on the ability to entangle ions. Entanglement has been referred by Einstein as “spooky” and is one of the most counterintuitive predictions of quantum physics. At Sussex we have developed a scalable method to create entanglement using microwaves. This project may involve some theory, programming and experimental work. You will evaluate how to increase entanglement gate fidelities in order to reduce error rates within quantum computing operations.
- Quantum simulations with trapped ions (Ref. WH6)
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Richard Feynman pioneered the idea that instead of trying to simulate quantum systems with classical computers, it is much more efficient to use a quantum system that can be controlled in the lab to simulate another quantum system one would like to understand. There is a vast range of possible quantum simulations that can be performed using trapped ions from all areas of physics, including effects of Einstein’s theory of special relativity, the Kibble-Zurek mechanism, particle creation moments after the big bang and complex many-body phenomena such as quantum biology and quantum chemistry. The aim of this project is to analyse and further develop theoretical proposals for quantum simulations and carry out the corresponding experiments using trapped ions at Sussex.
- Developing a portable quantum sensor (Ref. WH7)
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Sensors form a major part of every-day technology and can even be found in modern day mobile phones. The applications are endless and a continuous effort is underway to improve their sensitivity. A quantum sensor makes use of the ‘strange’ effects of quantum mechanics to provide a step-change in the achievable sensitivity and is seen as one of the most promising quantum technologies to be commercialised in the near future. The IQT group is working on developing a portable ion-trap based magnetometer which can be used to sense magnetic fields with unparalleled sensitivity. Within this project you will familiarise yourself with how a quantum sensor works. In order to develop a portable quantum sensor, an experiment filling an entire lab needs to be reduced to the size of a shoe-box. You will learn about the core components making up our ion trap based magnetometer and develop ways to significantly reduce their size. This will include the development of miniaturised laser and vacuum systems.
- Communicating quantum technology (Ref. WH8)
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A famous quantum physicist once proclaimed that the only physicists who understand quantum physics are the ones who know that they don’t understand it. Within this project you will analyse the factors that lead to the difficulty in obtaining an intuitive understanding of quantum physics. Once these factors become clear, you will devise strategies to circumvent such problems and create a strategy to communicate quantum technology research to a number of different target groups such as the general public, A-level students and undergraduate physics students. You will then create appropriate materials such as websites, simulations, applets, handouts and hand-on demonstrations in order effectively communicate quantum technology research. You will also measure the efficiency of the created strategy and materials by analysing its effect on various target groups. Experience in making highly sophisticated websites and interactive simulations is critical.
- Dr Matthias Keller
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Ion trap for the quantum internet (Ref. MK1)
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In order to create a ‘modem’ for the quantum internet, single atomic ions must be coupled to an optical cavity. In my group we currently operate four ion traps to explore schemes to implement such a modem to transfer the quantum information from an ion to photons which carry the information through the network. In this project you will design, build and test a novel ion trap which is combined with an ultra-small optical fibre cavity. The project starts from the design and simulation of the trap and follows the trap development through to the actual implementation.
- Micro-controller based Signal Processing (Ref. MK2)
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Electronic circuits are indispensable in modern quantum technology. Often, the required processing of signals can’t be easily done with analogue electronics. Using fast analogue-to-digital converters together with a micro-controller can serve as a versatile signal processing unit. The signal is digitalised and processed by the programmable micro-controller and then converted back into an analogue signal.
The goal of this project is the programming of a PIC micro-controller to serve as a versatile signal processing system. It includes the design and test of peripheral electronic circuits.
- Lasers for the quantum internet (Ref. MK3)
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Lasers are an indispensible tool to create the quantum version of the internet. They are required to cool, manipulate and prepare trapped ions in a specific quantum state (qubit state). Furthermore, lasers are needed for controlling the interaction of ions and photons to generate single photons or for long distance ion-photon entanglement, building blocks for the quantum internet. As a reference for all the lasers we build a ultra-high precision laser which is referenced to a state-of-the-art optical cavity. In this project, you will improve the performance of the laser and help to transfer its stability to other lasers in the lab. Furthermore, you will be working to implement these lasers in our quantum internet experiments.
- Testing the foundations of physics with lasers (Ref. MK4)
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- Dr Fedja Orucevic
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
- Dynamics of trapped ions (Ref. FO1)
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The ability to confine atoms to a defined small region in space has led to many advances in science, especially in atomic physics. Today, a great variety of such traps exist and are routinely used in many laboratories around the world, investigating fundamental questions such as quantum non-equilibrium physics as well as applications such as new time standards in atomic clocks and in precision measurement of gravitational and electromagnetic fields.
In this project, we will study the dynamics of particles in externally shaped potentials, and theoretically determine the conditions under which the motion is predictable, stable and bounded, so that the potential forms a trap. Furthermore, we will explore when and how instabilities start to play a role at the onset of chaotic motion. Experimentally, we will design and build a simple trap by an appropriate combination of DC and AC charged electrodes. While this assembly will be capable of trapping individual atoms, we will test it with ionised micro-beads whose motion is easily observable with appropriate commercial optics, allowing us to compare experimental results to theoretical predictions. The balance between theory and experiment can be tailored to suit the interests of the students and to pursue the most promising discoveries made during the project.
- Mach-Zehnder interferometer and quantum eraser (Ref. FO2)
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We will study and understand basic optics with a focus on polarization of light and how it can be influenced by waveplates, polarisers and beam splitters. We will set up a Mach-Zehnder interferometer to create two indistinguishable paths along which light from a single source propagates. The contrast of the resulting interference pattern is reduced when the indistinguishability of the paths is lifted, i.e. when (partial) which-way-information becomes available by controlling the polarisation in the different beam paths. We will analyse this effect in detail and discuss its relation to the famous wave-particle duality in quantum physics. In this context, we will investigate also the quantum eraser effect by showing that the interference pattern will reappear if the gained information is erased by introducing a polariser after the two beams have been overlapped again. This experiment is related to fundamental physics, quantum optics, decoherence and the quantum-to-classical transition.
- Noise in cold atom imaging (Ref. FO3)
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Laser cooling can bring gases of atoms to temperatures of less than a millikelvin above absolute zero. In this project, you will investigate how clouds of about ten million rubidium atoms at these temperatures can be detected. The most common technique is absorption imaging: the cloud is exposed to monochromatic laser light tuned to a strong atomic resonance. By absorbing the light, the atomic cloud casts a shadow into the light beam, which is then detected on a CCD camera. Alternatively, the light re-emitted from the atoms (fluorescence) can be collected on a photodiode or a CCD chip. We will initially explore these two imaging techniques theoretically, in particular in view of questions of high practical relevance, e.g. the expected signal-to-noise ratio of the detection as a function of experimental and technical parameters, such as atomic density, light intensity, the quantum efficiency of the camera, optical properties of the lenses used etc. Based on these calculations and corresponding expectations for experimental outcomes, you will take a series of images in an existing experimental setup and interpret the obtained images in terms of their noise. In particular, the distinction between photonic noise and atomic noise will be relevant.
- Conveyor belt for quantum gas magnetometer (Ref. FO4)
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Recent rapid advances in the field of laser cooling and trapping with routine preparation of nanokelvin cold samples of quantum degenerate gases (Bose-Einstein condensates) have led to new concepts in quantum technologies, e.g. for computing, communication and metrology applications. In our research lab we are working on microscopic magnetic field sensors, whose record field sensitivity is reliant on the low temperature and the quantum properties of the gas.
An important component of the microscope apparatus is a mechanism to move the sensor probe (a trapped sample of Bose-condensed atoms) to very close (microns) proximity of the sample. This transport from the atom cooling region to the sample region over a few centimetres will be done magnetically. The goal of the project is to design and test a printed circuit board (PCB) that can produce the necessary time-varying magnetic fields. We will use ultrahigh vacuum (UHV) compatible multi-layer technology and will characterise the device during operation of our ultracold atom chip-based “conveyor belt”. The project involves magnetic field calculations, computer aided PCB design and experimental work on an existing ultracold atom setup.
- Acousto-optic modulator (Ref. FO5)
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Mixing acoustic waves with light has wide applications ranging from laser printers to atomic physics experiments. In this project, you will study a key acousto-optic device, the acousto-optic modulator (AOM). A transparent crystal is simultaneously exposed to orthogonally propagating sound and laser waves, such that the laser light is diffracted. You will observe and interpret the diffraction pattern and see how controlling the parameters of the sound wave changes it. In interferometric measurements (beating) you will determine the frequency shifts induced by the AOM. This project is mainly experimental, but will include some theoretical aspects as well.
- Lasers in modern atomic physics (Ref. FO6)
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Lasers are essential tools in atomic physics experiments, as their intrinsic coherence and small linewidths allow for a very precise control and manipulation of atoms. In a typical “cold atoms” experiment the lasers are used to perform a variety of tasks: cool the atoms by 6 orders of magnitude in temperature (down to few microkelvins), manipulate internal states of atoms (optical pumping), characterise atomic ensembles (fluorescence and absorption imaging), etc…
In this project we propose to integrate a new laser line into our cold atoms experiment. Successful implementation and characterisation of a laser will allow the student to put into practice and expand their knowledge in many areas of physics: quantum physics, optics, electromagnetism, electronics and feedback theory, programming and simulation.
Furthermore, by operating the laser in a real cold atom experiment the student will have the opportunity to get acquainted with many aspects of modern atomic physics, such as laser cooling and Bose-Einstein condensation.
- Magnetic traps for ultracold atoms (Ref. FO7)
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Using tunable narrow-band laser sources atomic gases can be cooled to microkelvin temperatures. The corresponding thermal energies are sufficiently small to be comparable to magnetic Zeeman shifts induced by magnetic fields on the order of the Earth’s field. In this project we will explore how microscopic traps for cold atoms can be formed by passing currents through patterned conductors on microchips. We will start out with simple two-dimensional geometries and static fields and move on to higher complexity involving oscillating currents in the radio and microwave frequency range (MHz to GHz) and three-dimensional layouts. Such magnetic (micro)traps are used to store atoms for further cooling beyond the capability of lasers as well as for experiments and technological applications of quantum physics.
- Dr Jose Verdu Galiana
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For more information on the projects listed below, please use the details provided on the supervisor's profile page.
Development of Quantum Microwave Microscope
Background: The aim of this ambitious project is the development of a pioneering quantum microwave microscope using a single electron captured in a chip ion trap as the quantum microwave sensor/emitter. An electron in a trap is known as a geonium atom, an artificial quantum object with properties designed and manipulated by the experimenter with great control. The trapped electron has demonstrated as an outstanding system for testing the laws of physics with extremely high accuracy. In the geonium chip laboratory at Sussex (www.geoniumchip.org) we are developing a novel chip ion trap, which will make use of a trapped electron as quantum transducer of microwave radiation. The electron is the most accurate and sensitive detector and emitter of microwave fields, with ultimate single photon sensitivity. This allows for implementing the most advanced quantum metrology techniques for testing and measuring systems (for instance human tissue or materials) with microwave radiation, using entanglement and other quantum resources. Many applications can be envisaged with such an ultra-sensitive quantum sensor/emitter of microwaves. In our lab, we aim at developing a revolutionary microscope, operating in the microwave domain, with the geonium atom technology. This might allow for surpassing the current sensitivity limitations of microwave microscopes, enabling unprecedented observation possibilities of natural or man made systems. Several experimental projects are offered. The details of the project will be discussed with the students depending on their interests. Relevant technologies that will be used include, superconductivity, RF electronics, Microwave Engineering, Cryogenics, magnetic field design and measurements, chip design and simulation, and others. Excellent candidates might be offered a fully funded PhD position after the successful completion of the project.
Transferable Skills: Lab Skills, circuit design, Microwave Engineering, Superconductivity, RF-Electronics, Lab-View, data analysis, cryogenics, vacuum techniques, FFT analysis, Vector Network Analysis, chip design and simulation, team work (with people inside and outside Sussex).
References:
[1] J. Verdu, New J. Phys. 13, 113029 (2011)
[2] A. Cridland et al, Photonics 3, 59 (2016)
[3] M. Lanzagorta, Quantum Radar, Morgan and Claypool (2011)
- Magnetic field Stabilisation (Ref. JVG1)
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This experimental project aims at developing a superconducting shield for eliminating any externally induced magnetic field fluctuations in the trapping region. The stability of the magnetic field is critical for a good characterisation of the trapped particles and for the operation of the geonium chip as a microwave photon sensor/emitter for quantum microwave microscope and quantum radar applications. In this project the student will design, simulate, fabricate and measure closed-loop superconducting structures using YBCO or NbTi. These structures will be measured using a Hall sensor and a liquid nitrogen or liquid He cryostat.
- Detection of one trapped electron (Ref. JVG2)
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This experimental project will focus on optimising the cryogenic detection system employed for observing one single trapped electron for the Quantum Microwave Microscope / Quantum Radar. The detection system essentially consists of one superconducting helical resonator and a cryogenic amplifier made with discreet components (pHEMT FET transistors). The project will focus on the measurement and characterisation of the different types of available GaAs transistors capable of operating at cryogenic temperatures. After the characterisation of the transistors a low noise cryogenic amplifier will be implemented and measured using a vector network analyser. The project involves the use of LabView, Mathematica, ADS software plus RF test and measurement equipment and 4K cryostats.
- Cooling the electron down to the quantum ground state (Ref. JVG3)
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This experimental project will focus on the development of a 80 mK cryo-cooling system capable of cooling the electron’s motion down to its quantum ground state. The 80 mK cryo-cooling system will operate an Adiabatic Demagnetisation Refrigerator which will be coupled to a closed-cycle Gifford-McMahon 4K cryo-cooler. The project will involve the design, fabrication and measurement of several components, such as thermalisation boards, noise filters, RF and MW attenuators, current leads, heat sinks and others, all necessary for achieving the extremely low temperature regime of 80 mK.
- Implementation of Microwave Quantum Illumination with trapped electrons (Ref. JVG4)
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This experimental project will focus on implementing the quantum illumination protocol using one electron as the sensor and emitter of entangled microwave radiation. This goal is critical for quantum microwave microscopy and quantum radar applications. This project is very ambitious and will only be offered to first-class candidates with the possibility to continue with a fully funded PhD position after the end of the MSc. The details of the project will be discussed with the candidate.
- Nanomaterials and Energy
- These projects are suitable for students on the MSc Nanomaterials and Energy course.
- Dr Alice King (Ref AAK1)
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For more information on the projects below, please use the details provided on the supervisor's profile page
- Nanomaterial scaffolds for tissue engineering
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How the structure of cells alters and develops in response to the substrate and its neighbours is critical in the development of tissue, and also in the role of cancer. Increasingly the role of the topographical and mechanical properties of the cell surroundings are being identified as key to the structural dynamics of a cell sensing hardness, elasticity and stability at the nanoscale. In this project we will design tissue scaffolds from various nanomaterials (including graphene and transition metal dichalcogenides), with a range of physical and chemical properties that we can optimise and tailor to stimulate various cellular responses and control tissue growth.
- Prof Alan Dalton (Ref AD1)
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For more information on the project listed below, please use the details provided on the supervisor's profile page
- Electromechanical properties of nanostructured networks
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In this project, the student will fabricate and characterize composite materials based on percolating networks of 2D materials infiltrated into a flexible polymer matrix. It is expected that such systems should show large changes in electrical conductivity as the materials are strained. Ultimately, the composite material could act as an ideal strain sensor in a wide variety of applications, particularly in healthcare - where sensitive strain measurements are crucial in monitoring heartrate, chest motion, joint bending and patient ventilation. Elsewhere, the material could be incorporated into wearable technologies for monitoring sport performance; and may lead to new advances in "soft robots" that stimulate the properties of biological systems.