Department of Physics and Astronomy

MSc Projects

Complete MSc project list for Physics and Astronomy 

The complete list of MSc projects offered for 2019-20 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

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

 For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Primordial black hole relics as dark matter (Ref. CB1)

If black holes formed during the very early universe they could potentially form with any mass, unlike black holes which form later from collapsed stars. Low mass black holes could evaporate quickly due to Hawking radiation, and the final state of this evaporation is unknown. It is possible that black holes leave a relic (with a mass presumably comparable to the Planck mass), and such Planck mass relics are one of the many dark matter candidates.


The goal of this project is to first summarise the arguments for and against the existence of black hole relics, and then study models of the early universe which could give rise to the existence of such black hole relics. How much fine tuning is required in order that the relic density is equal to the density of dark matter, and what types of observations might be able to detect or rules out the existence of black hole relics?
I would strongly recommend any student taking this project to take the cosmology and advanced cosmology modules. GR is also a recommended module. This challenging project will require a good level of mathematical/analytical skills.

Constraining the curvaton inflationary scenario (Ref. CB2)

Most cosmologists believe that an epoch of inflation took place during the very early Universe, which is a period of accelerated expansion during which quantum mechanical perturbations set the initial conditions for the perturbations observed in the universe today, acting as the seeds of stars and galaxies. Not much is known about this period of inflation beyond the fact the perturbations generated must match the observed statistical properties of the temperature perturbations observed in the cosmic microwave background, for example using the Planck satellite.


The observations are consistent with a single scalar field having generated the perturbations as well as having led to the epoch of inflation, but the data is also consistent with more complicated models such as the curvaton scenario, in which the curvaton generates the initial perturbations and a separate inflaton field is responsible for causing inflation. The curvaton scenario is a classic example of multifield inflation.


The first goal of this project is to summarise the differences between single and multifield inflation, in terms of the theory and observables. The principal goal is to calculate how the most recent observational constraints on the early universe constrain the curvaton scenario and to study how future observations might be able to either detect or rule out the curvaton as having been responsible for the origin of all structures.


I would strongly recommend any student taking this project to take the cosmology and advanced cosmology modules. QFT is also a recommended module. This project will require a good level of mathematical/analytical skills and numerical skills would also be useful.

Dr Paul Giles

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Searching for galaxy groups infalling onto massive galaxy clusters(Ref. PG1)

Clusters of galaxies are the largest gravitationally bound objects in the Universe, and the growth of galaxy clusters is a sensitive and powerful probe of cosmology. Galaxy clusters form via the mergers of lower mass systems, known as galaxy groups, and continue to grow through the continual accretion of these groups. X-ray observations of galaxy groups provide the opportunity to confirm the presence of a group system. However, the study of infalling groups is hampered due to their lower mass, and hence lower X-ray surface brightness. In this project you will search for galaxy groups using optical data, and study these groups in the outskirts of clusters through the stacking of X-ray data.

Prof Mark Hindmarsh

PLEASE NOTE PROF HINDMARSH IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 19/20.

Production of Gravitational Waves in the Early Universe (Ref. MHI2)

Violent processes in the early universe - such as phase transitions - would have generated gravitational waves. In this project, the student can examine possible sources from new physics at very high energy, calculate the amplitude and frequency spectrum of the resulting gravitational waves, and assess the possibilities for detection by a future space-based gravitational wave observatory. Some prior experience of the numerical solution of differential equations (with e.g. Python or Matlab) is needed.

Recommended modules: General Relativity, Quantum Field Theory, Early Universe. 

Prof Ilian Iliev

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)

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)

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.

Prof Antony Lewis

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Numerical optimization for early-universe evolution algorithms (Ref. AL1)

Many numerical results in cosmology result from integrating Bessel-like equations, typically evolving a large set of 100s of equations simultaneously. This project is for people who are interested in a computational project, to investigate how to best exploit SIMD and similar vectorization techniques to speed up these calculations. Specifically, a relatively new language called Julia makes writing vectorised code relatively easy, and this project is to test whether making use of it can save significant computational time, and develop a prototype optimized code. If there is time this could lead to re-writing a widely used CMB cosmology code in Julia, incorporating the new optimization techniques.

Dr Jon Loveday

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

A halo catalogue for the GAMA survey (Ref. JL1)

The Galaxy and Mass Assembly (GAMA; http://www.gama-survey.org/) survey provides highly-complete spectroscopy over three equatorial fields. A widely-used product from this survey is a galaxy group catalogue (Robotham et al 2011, MNRAS, 416, 2640), defined using a friends-of-friends algorithm, which provides reliable identification of rich groups with five or more members. The aim of this project is to build an alternative halo catalogue, along the lines of Munoz-Cuartos and Muller (2012, MNRAS, 423, 1583), which will include much lower richness systems, thus widely extending studies of the relation between galaxies and their host dark matter halos.

The abundance of dwarf galaxies (Ref. JL2)

Distances, and hence luminosities, of intrinsically faint ('dwarf') galaxies can only be determined spectroscopically if they are nearby, and hence apparently bright. This limits our understanding of the abundance of dwarf galaxies relative to their brighter counterparts: a key prediction of the cold dark matter paradigm of structure formation. In this project you will measure the cross-correlation of bright and faint galaxies in the GAMA survey regions in order to infer the abundance of dwarf galaxies to lower luminosities than has been hitherto possible.

Dr Rajesh Mondal and Prof Ilian Iliev

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Constraining cosmic reionization history and model parameters using machine learning (Ref. RM/II1)

Observations of the redshifted 21-cm signal from neutral hydrogen are a very promising probe of the Epoch of Reionization, which spans the first billion years of the Universe. There is a considerable ongoing observational efforts to detect this signal. For the reliable interpretation of the results, it is important to establish a method to derive constraints on the reionization parameters from the observed 21-cm data. In this project you will work on developing a method for constraining these parameters using a machine learning method called artificial neural networks (ANN). This will be trained based on available simulation data, giving you experience in working with large data sets. A working knowledge of Python or similar programming language is expected.

Prof Seb Oliver

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)

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

PLEASE NOTE PROF ROMER IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 19/20.

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)

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 XMM 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 ultimate goal of the XCS is to constrain models of Dark Energy, but a student would be able to choose from a variety of different science and analysis applications. 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).

Dr David Seery

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Automated evaluation of large-scale structure correlation functions (Ref. DS1)

Over the next decade, progress in early universe cosmology will be driven by data arriving from large-scale galaxy surveys such as Euclid, DESI and LSST. To make use of this information, theorists must use their models to provide predictions for galaxy-survey observables (typically correlation functions or their Fourier-space counterparts) at a suitable precision. One possibility is to use 'standard perturabtion theory' (or 'SPT'), which is roughly the equivalent in cosmology of Feynman diagram calculations in particle physics.

The disadvantage of Feynman methods is that, as the calculation becomes more accurate, they require evaluation of a very large number of diagrams. Worse, to get maximum information (especially for modified gravity) we often wish to work in 'redshift space', which introduces new angular dependences that make everything more complicated. Beyond a certain point hand calculation becomes completely impractical. In particle physics this problem has been solved by using a suite of software packages to automate calculations, and something similar is now required in cosmology. We have developed a prototype tool to compute SPT correlation functions up to one loop, which we are using to evaluate the one-loop power spectrum of biased halos in redshift space.

In a modified gravity model the bispectrum (a measure of three-point correlations) may be a more sensitive discriminant, but it is underexplored because of the long calculations that have traditionally been involved. In this project you will adapt our software to compute the full angular dependence of the redshift space bispectrum (initially at tree-level, later at one-loop if things go well), in LambdaCDM and some specimen modified gravity models.

You will need to learn about structure formation in the early universe, and the perturbative solution of the equations that describe it. You will also need to learn how to convert these solutions into predictions for the statistical properties that can be measured in realsitic surveys. Extracting the angular dependence requires some mathematical sophistication with special functions. You will likely to find that this project strongly complements the Advanced Cosmology course. On the programming side, our codes are written in C++ and so you will have a head start if you are already familiar with this language.

Dr Robert E. Smith

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)

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.

Estimating the Galaxy Power Spectrum from a Galaxy Redshift Survey (Ref. RS2)

In this project we will look at how one measures the power spectrum using a state of the art galaxy redshift survey. The galaxy power spectrum is one of the key observables for constraining the cosmological model. We will pay special attention to optimal strategies for maximising the information content.

Prof Peter Thomas

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Making galaxies (Ref. PT1)

The formation of galaxies is one of the outstanding problems in contemporary astrophysics. We understand how dark matter collapses under its own gravity to form small clumps that gradually merge together to form larger and larger "galactic halos". However, the simplest models of how galaxies form within these halos gives properties that disagree wildly with observations. It seems that we need huge amounts of feedback of energy from supernovae (exploding stars) and active galactic nuclei (supermassive black holes).

Simulations of galaxy formation are in their infancy and can not yet reproduce a realistic galaxy population. Instead, major advances have been made using "semi-analytic models" for the growth of galaxies within dark matter halos.

This project can be set at a variety of levels depending upon the experience of the student:
* Comparing the predictions of semi-analytic models to the latest observational data.
* Adapting an existing semi-analytic model to try to better reproduce the observations and/or give greater insight into the processes governing galaxy formation.

You will work with the latest observational data from large galaxy surveys such as SDSS (the Sloan Digital Sky Survey) or GAMA (Galaxies and Mass Assembly), and simulations from the Virgo Supercomputing Consortium.

Familiarity with Python/Matplotlib is desirable.

Dr Stephen Wilkins
The First Light and Reionisation Epoch Simulation (Ref. SW1)

The First Light and Reionisation Epoch Simulation (FLARES) is a suite of hydrodynamical simulations of the early Universe designed to be matched to observational constraints from the upcoming Webb Telescope, Euclid Satellite, and Square Kilometre Array. In this project you will use FLARES to make predictions for one of these projects. This will project will involve becoming familiar with both state-of-the-art galaxy formation simulations and upcoming observatories.

Atomic, Molecular and Optical Physics

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

For more information on the projects listed below, please use the details provided on the supervisor's profile page.PLEASE NOTE PROF GARRAWAY IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 17/18.

Decay of quantum systems (Ref. BG1)

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)

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)

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

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)

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)

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)

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)

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)

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)

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)

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)

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

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)

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)

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)

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)

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)

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

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)

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)

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)

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.

Conveyor belt for quantum gas magnetometer (Ref. FO4)

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)

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)

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)

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 Alessia Pasquazi

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Ultrafast Optical Micro-Combs

Background: optical Frequency Combs (OFCs) are often referred to as optical rulers: their spectrum consists of a precise sequence of discrete, equally spaced lines, which represent precise “marks” in frequency. The importance of combs was recognized in the 2005 Nobel Award to T. W. Hänsch and J. Hall. There is a common belief that OFCs will have a key role in signal processing for the synthesis and the measurement of an arbitrary signal, directly impacting fields ranging from optical telecommunications to microwave photonic. Finally, OFCs are expected to have a strong impact in spectroscopy for the detection of low concentration gases, and to find applications in the monitoring of hazardous gases in the atmosphere, improving the security and the health of the population, but also in the manufacturing process of e.g. electronic industry or pharmaceutical, or in breath control, providing a non-invasive medical scanning instrument.

In the UK, miniature atomic clocks are recognized as a 2.0 quantum technology (EPSR-DSTL UK quantum technology landscape 2014). Portable atomic clocks are recognized as crucial for developing the next generation of sensor, telecommunication, computing and navigation systems. Currently, there are several research programmes worldwide to develop novel, portable atomic clock systems based on ultracold atoms or ions. For those systems, compact OFCs are a key technology.

Optical frequency comb from quadratic nonlinearities (Ref. AP1E for the experimental profile and AP1T for the theoretical profile)

This project is part of the research action on ultrafast optical frequency combs of the University of Sussex within the Quantum Technology Hub on Sensors and Metrology. In the 2012 Dr. Pasquazi and co-workers demonstrated for the first time a novel type of laser (you may refer to, Nature Commun. 3, 765 (2012) and Opt. Express, 21, 13333 (2013)) allowing for an agile generation of optical combs. This type of source bases its operating mechanism on optical cubic nonlinearities in optical microresonators. Such nonlinearities are quite weak in highly transparent optical materials (silica and other glasses), hence high-Q factor resonators are required to enhance the internal field in order to induce a significant nonlinear dynamics.

Quadratic optical nonlinearities present in non-centrosymmetric crystals are in general stronger than their cubic counterpart. However the inner mechanism inducing optical combs in a resonator cannot operate with quadratic nonlinearities. The key idea of this research project is to ‘cascade’ two quadratic processes to obtain an equivalent cubic nonlinear process which is orders of magnitude stronger than its ‘natural’ equivalent. Although this process is very well explored in many bulk geometries, it has been never explored in resonating devices, nor has it been exploited to generate an optical comb. The project consists of two parts, hence we seek two different profiles:


AP1E: you will be engaged in the experimental demonstration of the first optical frequency comb based on quadratic nonlinearities. You will familiarize with the physics of quadratic optical nonlinearities and also with the experimental challenge of building a nonlinear laser cavity. You will receive specific experimental training and eventually design and assemble (in collaboration with a team) the device.


AP1T: you will be engaged in the development of the theoretical photonic background of the system. You will acquire competence of high-performance electromagnetic simulations of systems based on coupled nonlinear Schrödinger equations. You will receive specific training on modelling electromagnetic and photonic problems and you will contribute to the design of an electromagnetic simulator capable of reproducing the nonlinear dynamics of the cavity.

Synchronous pumping of nonlinear micro-combs (Ref. AP2)

Micro-combs are devices capable of generating optical frequency combs base on optical microresonators. The most common approach to generate the comb is to couple into the device a monochromatic continuous-wave laser light with wavelength matching one resonance of the microresonator. In high-quality microresonator the long cavity life-time produces an internal field enhancement. The internal intensity is then very high and capable to excite the inherent resonator nonlinearity, resulting in a phenomenon known as optical parametric oscillation (Kippenberg et al. Science 332 555, 2011). For a number of physical reasons the degree of control on such a phenomenon is very limited and obtaining a good quality comb (i.e. a comb with spectral lines oscillating in a perfectly synchronized manner) is a real challenge. In this project you will experiment a novel approach, pumping a nonlinear resonating device with a train of ultrafast sub-ps optical pulses (hence you will acquire a specific competence in ultrafast lasers). In particular you will investigate the potential degree of freedom given by this approach targeting the demonstration of a high-quality optical frequency combs. You will develop a significant understanding of the physics of nonlinear optical devices and also significant first-hand experience with ultrafast laser sources.

Dr Marco Peccianti

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Terahertz ultrafast science

Background:  The core interest of the Emergent Photonics Lab is Ultrafast Photonics with two major research lines in Terahertz Photonics and Complex Photonics. TIMING is a multidisciplinary project funded by the European Research Council (for a value of about 1.7 Million of GBP). It involves novel approaches to imaging and exotic nonlinear field-matter interactions, including processes that generate Terahertz waves. Key to the project success are elements directly inherited from the propagation in complex optical media. This project transversely intersects the kernel of our research interests. The outcomes are likely to have a key impact in several domains, from environmental detection to metrology, security, pharmaceutical manufacturing, medical and others. These MSc projects will complement our efforts in diagnostic technologies based on nonlinear field-matter interaction with ultrashort pulses. The candidate will gain access to the Emergent Photonics Laboratory (EPic) http://www.sussex.ac.uk/physics/epic/, a 110m^2 facility that comprises a very large spectrum of state-of-the-art photonic equipment (representing a total investment exceeding 1.1 Million of GBP from different funding sources):

-High energy ultrafast optical sources (5mJ@90fs Ppeak>50GW)

-Several types of ultrafast laser oscillators (Ti:Sa, Er-doped fiber oscillator, optical parametric oscillators)

-30m^2 of optical tables

-Two atomic-clock stabilised ultrafast optical combs

-Ultrafast microwave-on-optics diagnostics (i.e. generators, modulators and detectors)

-Ultrafast electronic acquisition systems (80GS/s with bandwidth >36GHz)

-Several diagnostic workbenches for terahertz, mid-Infrared and optical ultrashort pulses

-Terahertz imagers

-High Energy Terahertz sources

The project deploys within a fertile international collaboration of researchers. The successful candidate will join an interdisciplinary team.

Ultrafast Terahertz Imaging (Ref. MP1)

In this project, extremely short Terahertz pulses (ultrafast) will be used to produce a full 3-Dimensional electromagnetic image of an object, revealing its internal structure. This specific imaging approach is based on the Time-Domain Spectroscopy, a specific probing technique that does not have equivalent in other electromagnetic bands: the internal parts of an object are perceived exploiting delays between the generated electromagnetic echoes, in a method somewhat similar to ultrasound imaging. In this project you will acquire the necessary physical understanding of nonlinear field-matter interaction at the basis of the Terahertz generation detection. You will be part of the team that will design the imaging system and directly manage the generation from intense optical pulses. You will be also engaged in the reconstruction (electronic acquisition + software) of the electromagnetic 3D-image from the detected signals.

Mimetic material for the Terahertz domain (Ref. MP2)

In this research project we explore structures that can acquire specific Terahertz electromagnetic properties from a second object upon contact. In this research endeavour you will develop understanding on simulating plasmonic devices, i.e. electromagnetic structures that operates thanks to a coupling between photon and electrons. This project is led by the University of Sussex in collaboration with the INRS-EMT (Canada). As part of our research team you will design a Terahertz electromagnetic structure suited for the purpose that will be fabricated by our team. You will also test the devices in order to feedback the design process. Details on the specific targeted technologies and application will be discussed directly with you possibly under a non-disclosure agreement.

Dr Jose Verdu Galiana

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)

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)

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)

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)

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

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

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)

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.

ATLAS Jet Physics (Ref. LA2)

Precision measurements of interactions and couplings of the Higgs Boson (e.g. Yukawa coupling) can allow us to propose, develop and test increasingly accurate theories of nature. At around 1 billion particle collisions per second at the LHC both hardware and software techniques are required to filter events of interest from those that aren’t through the ATLAS Trigger. Following this, determining whether an event of interest actually contains a signal we are looking for (and not a closely-resembling background) requires multivariate analysis of physically observable data, particularly within Hadronic Jet Substructure. Use of Jet Substructure both in the ATLAS Jet Trigger, and for assessing and improving Jet Reconstruction and Grooming at analysis level is therefore of great importance.

Using of both ATLAS data and Monte Carlo simulations the student will develop analysis programmes in the C++ programming language, using the ROOT analysis framework, and through the use of python.

The ability to use these skills and techniques are widespread within particle physics and extremely desirable from an industry perspective.

Prof Alessandro Cerri

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

The ATLAS Hardware Track Trigger (Ref. AC1)

The ATLAS experiment at the Large Hadron Collider will employ custom-built electronics to identify and reconstruct particles in its detector. The ATLAS Sussex group is participating in the construction of this cutting-edge electronics system: the Hardware Track Trigger. In this project you will participate to the design and/or testing of prototypes, working with cutting-edge electronics devices and tools to address a forefront research problem in particle physics. The project can suit students familiar with either software, firmware or electronics design and development skills, participating in the development of a system with potential interdisciplinary applications (Image processing, medical imaging, etc.).

You will be using either advanced simulation, firmware development or electronic tools to benchmark, test or participate to the design of such system, in collaborating with the ATLAS Sussex group members. This project is suitable for students with a keen interest in big data, machine learning and electronics. Either Python/C/C++ programming or familiarity with firmware and electronics development will be needed. You will be learning advanced machine learning and big data techniques, sharpen your knowledge of electronics and forefront high speed digital electronic systems.

Super-accelerated Machine Learning (Ref. AC2)

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 ATLAS detector data, to tackle the complexity of identifying particles in the ATLAS 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. AC3)

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.

R&D With Associative Memories (Ref. AC4)

Associative Memories (AM) are dedicated high-speed electronic devices implementing the real-time identification of patterns in electronics data. They are employed - for instance - in the identification of particle trajectories in the ATLAS detector at the CERN Large Hadron Collider. The computational power implemented in a AM device is of the order of 50 million MIPs, with modern intel processors provide typically something of the order of 100000 MIPs). This computational power is best exploited in specific problems where patterns need to be identified in data in real time, providing effectively a very focused tool to address Machine Learning problems, in some sense analogous to individual nodes in a neural network.

With this project you will be exploring - in collaboration with senior and junior scientists - the flexibility of Associative Memories, exploiting their performances in ways that have not been probed so far: multiple layers, different levels of information abstraction and the integration in automatic learning algorithms to implement Associative-Memory based machine learning.

This project is suitable for students with a keen interest in big data, machine learning and electronics. Either Python/C/C++ programming or familiarity with firmware and electronics development 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.

Prof Antonella De Santo

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Supersymmetry (Ref. ADS1)

Supersymmetry (SUSY) is one of the well-motivated theories beyond the Standard Model, which could be realised in nature at TeV-scale energies. SUSY could for example hold the key to explaining the nature of Dark Matter. 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 BSM phenomena. Sussex has a leading role in the search for supersymmetric signals in a number of flagship analyses at ATLAS, including SUSY searches in multileptonic final states. We are also involved in preparations for future collider experiments, including, but not limited to, upgrades of the ATLAS experiment for the High-Luminosity LHC (HL-LHC) phase. You will become integrated within the Sussex ATLAS group for the duration of your project, interacting collaboratively on a regular basis with faculty members, research staff and other students. You will perform a computer-based analysis of simulated (and possibly real) data from ATLAS or a future collider experiment. The detailed scope 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 the required computing skills (e.g., C++ programming and ROOT analysis framework) rapidly. A good disposition towards teamwork is also essential.

Recommended resources for initial reading:

[1] S.P.Martin, A Supersymmetry Primer, https://arxiv.org/abs/hep-ph/9709356

[2] ROOT homepage, https://root.cern.ch/

[3] ATLAS experiment public webpage, https://atlas.cern/

Dr Elisabeth Falk

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)

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

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)

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. Reconstructing the tracks of the particles relies on understanding the electric field in the vicinity of the anode plane wires. This project will involve modelling the structure of the electric field in the DUNE single-phase far detector and will optimise the wire placement in the anode plane.

Dr Fabrizio Salvatore
Search for susy partner of the top quark in decays to tau leptons with the ATLAS Detector at CERN (Ref. FS1)

Supersymmetry (SUSY) introduces a new symmetry between fermions and bosons, resulting in a SUSY partner particle (sparticle) for each Standard Model (SM) particle, with identical mass and quantum numbers except a difference by half a unit of spin. As none of these sparticles have been observed with the same masses as their SM partners, SUSY must be a broken symmetry if realised in nature, with the mass of the SUSY particles much higher than their SM partners. One of the most important sparticles is the SUSY partner of the top quark (stop), given that the top is the quark with the highest mass and therefore the one that couples strongly with the newly discovered Higgs boson. SUSY particles decay through cascades involving other sparticles until the lightest SUSY particle (LSP), which is stable, is produced. One possible decay of the stop quark would be through the SUSY partner of the tau lepton (stau), resulting at the end in final states with taus and missing energy from the escaping tau neutrinos and LSPs. In this project the student will analyse newly simulated MC events produced by the ATLAS experiment, where the decay chain stop--> stau is simulated. He/she will develop an analysis strategy based on the generated events to estimate the sensitivity of an analysis looking for final states containing one or mote tau leptons. The student will be developing the analysis program in the C++ programming language, using the ROOT analysis framework (visit the ROOT webpage).

Looking for Supersymmetry (SUSY) at ATLAS in tau+leptons final states (Ref. FS2)

Many SUSY models predict the presence of leptons in the final states of the interaction. These leptons (electron/muon/tau) come from long cascade decays of the SUSY particles and can be of the same flavour (ee/mumu/tautau) or of different flavour (emu/etau/mutau) and also have the same or opposite charge. In this project the student will be using advanced analysis programs to look for events in the ATLAS data and Montecarlo where 2 or more leptons are produced, and study the kinematical properties of these events that can be used to separate the signal event from the Standard Model background. In a second part of the project, the student will study events with 2 same flavour leptons + an additional lepton of different flavour in the final state, and study the increase in sensitivity to the SUSY parameter space with respect to analyses where only 2 leptons are produced. The student will be developing the analysis program in the C++ programming language, using the ROOT analysis framework (visit the ROOT webpage).

Theoretical Particle Physics

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 Andrea Banfi

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)

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).

Prof Xavier Calmet

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Project 1: Quantum Gravity and Quantum Field Theory (Ref. XC1)

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.

Prof Mark Hindmarsh
Numerical Simulations of Phase Transitions in the Early Universe (Ref. MHI1)

Modern particle physics predicts that the very early Universe went through a series of phase transitions, which may have produced extended objects called topological defects.  In this project the student will study phase transitions using numerical simulations: specific problems include the propagation and collision of phase boundaries, the formation and evolution of domain walls or cosmic strings. Basic knowledge of C is essential, and some familiarity with Unix would be useful.

Recommended modules: General Relativity, Quantum Field Theory, C++.

Production of Gravitational Waves in the Early Universe (Ref. MHI2)

Violent processes in the early universe - such as phase transitions - would have generated gravitational waves. In this project, the student can examine possible sources from new physics at very high energy, calculate the amplitude and frequency spectrum of the resulting gravitational waves, and assess the possibilities for detection by a future space-based gravitational wave observatory. Some prior experience of the numerical solution of differential equations (with e.g. Python or Matlab) is needed.

Recommended modules: General Relativity, Quantum Field Theory, Early Universe. 

 

Dr Stephan Huber

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Extra dimensions (Ref. SH1)

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)

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.

Supersymmetry (Ref. SH3)

Supersymmetry is one of the leading ideas for new physics. In the supersymmetric Standard Model each known particle obtains a partner of different spin. These so called superpartners are supposed to have masses around the electroweak scale and to date are intensively searched for at LHC. In the project you will analyse the supersymmetric particle spectrum of a specific realization of supersymmetry and draw conclusions on the possible signals at the LHC.

Prof Sebastian Jaeger

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)

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

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)

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)

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)

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)

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)

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.

Prof Veronica Sanz

PLEASE NOTE PROF SANZ IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 19/20.

Higgs couplings fits (Ref. VS1)

The student will learn the basic concepts of the Higgs mechanism and use data coming from the Large Hadron Collider to produce a fit of the Higgs couplings. The fit will be done in Mathematica, and then used to constrain new physics, such as Supersymmetry.

The holographic superconductor (Ref. VS2)

We will study the duality between strongly coupled condensed matter system (cuprate superconductor) and models in more than four dimensions of space and time with a bulk electromagnetic field. We will solve the classical equations of motion in five dimensions and build a dictionary with the condensed matter system parameters.

Tools for Dark Matter searches (Ref. VS3)

Dark Matter is searched in an array of experiments: telescopes on Earth, the space station, satellites in orbit, the Large Hadron Collider, underground mine facilities, etc. All this information should be pieced together to understand the nature of Dark Matter, but tools which connect these sources are often missing or inadequate. In this project we would learn about Dark Matter and experiments to search for it, and we will program interfaces among the different tools of Dark Matter already in the market. A good theoretical background and some experience with programming (C++, python) is required.

Materials Physics

For further details, please speak to the project supervisor using the contact details on their profile page

Prof Alan Dalton

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

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Mathematical Physics

For further details, please speak to the project supervisor using the contact details on their profile page

Prof Xavier Calmet

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Project Econophysics (Ref. XC2)

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.

Fundamental Physics with Quantum Sensors (Ref. XC3)

In this project you will learn how to probe physics beyond the standard model with tabletop experiments such as atomic clocks and other quantum sensors. It has recently become clear that a plethora of new phenomena could be investigated with such very low energy, but extremely precise, experiments ranging from very light dark matter candidates, domain walls, gravitational waves, dark energy to cosmological time evolution of fundamental constants. We will try to investigate such phenomena with a generic model independent approach using tools of quantum field theory.

Sussex Centre for Quantum Technologies

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

For more information on the projects listed below, please use the details provided on the supervisor's profile page.PLEASE NOTE PROF GARRAWAY IS NOT AVAILABLE FOR PROJECT SUPERVISION IN 17/18.

Decay of quantum systems (Ref. BG1)

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)

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)

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

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)

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)

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)

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)

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)

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)

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)

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)

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

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)

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)

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)

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)

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. 

Dr Fedja Orucevic

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)

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)

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)

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.

Conveyor belt for quantum gas magnetometer (Ref. FO4)

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)

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)

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)

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 Alessia Pasquazi

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Ultrafast Optical Micro-Combs

Background: optical Frequency Combs (OFCs) are often referred to as optical rulers: their spectrum consists of a precise sequence of discrete, equally spaced lines, which represent precise “marks” in frequency. The importance of combs was recognized in the 2005 Nobel Award to T. W. Hänsch and J. Hall. There is a common belief that OFCs will have a key role in signal processing for the synthesis and the measurement of an arbitrary signal, directly impacting fields ranging from optical telecommunications to microwave photonic. Finally, OFCs are expected to have a strong impact in spectroscopy for the detection of low concentration gases, and to find applications in the monitoring of hazardous gases in the atmosphere, improving the security and the health of the population, but also in the manufacturing process of e.g. electronic industry or pharmaceutical, or in breath control, providing a non-invasive medical scanning instrument.

In the UK, miniature atomic clocks are recognized as a 2.0 quantum technology (EPSR-DSTL UK quantum technology landscape 2014). Portable atomic clocks are recognized as crucial for developing the next generation of sensor, telecommunication, computing and navigation systems. Currently, there are several research programmes worldwide to develop novel, portable atomic clock systems based on ultracold atoms or ions. For those systems, compact OFCs are a key technology.

Optical frequency comb from quadratic nonlinearities (Ref. AP1E for the experimental profile and AP1T for the theoretical profile)

This project is part of the research action on ultrafast optical frequency combs of the University of Sussex within the Quantum Technology Hub on Sensors and Metrology. In the 2012 Dr. Pasquazi and co-workers demonstrated for the first time a novel type of laser (you may refer to, Nature Commun. 3, 765 (2012) and Opt. Express, 21, 13333 (2013)) allowing for an agile generation of optical combs. This type of source bases its operating mechanism on optical cubic nonlinearities in optical microresonators. Such nonlinearities are quite weak in highly transparent optical materials (silica and other glasses), hence high-Q factor resonators are required to enhance the internal field in order to induce a significant nonlinear dynamics.

Quadratic optical nonlinearities present in non-centrosymmetric crystals are in general stronger than their cubic counterpart. However the inner mechanism inducing optical combs in a resonator cannot operate with quadratic nonlinearities. The key idea of this research project is to ‘cascade’ two quadratic processes to obtain an equivalent cubic nonlinear process which is orders of magnitude stronger than its ‘natural’ equivalent. Although this process is very well explored in many bulk geometries, it has been never explored in resonating devices, nor has it been exploited to generate an optical comb. The project consists of two parts, hence we seek two different profiles:


AP1E: you will be engaged in the experimental demonstration of the first optical frequency comb based on quadratic nonlinearities. You will familiarize with the physics of quadratic optical nonlinearities and also with the experimental challenge of building a nonlinear laser cavity. You will receive specific experimental training and eventually design and assemble (in collaboration with a team) the device.


AP1T: you will be engaged in the development of the theoretical photonic background of the system. You will acquire competence of high-performance electromagnetic simulations of systems based on coupled nonlinear Schrödinger equations. You will receive specific training on modelling electromagnetic and photonic problems and you will contribute to the design of an electromagnetic simulator capable of reproducing the nonlinear dynamics of the cavity.

Synchronous pumping of nonlinear micro-combs (Ref. AP2)

Micro-combs are devices capable of generating optical frequency combs base on optical microresonators. The most common approach to generate the comb is to couple into the device a monochromatic continuous-wave laser light with wavelength matching one resonance of the microresonator. In high-quality microresonator the long cavity life-time produces an internal field enhancement. The internal intensity is then very high and capable to excite the inherent resonator nonlinearity, resulting in a phenomenon known as optical parametric oscillation (Kippenberg et al. Science 332 555, 2011). For a number of physical reasons the degree of control on such a phenomenon is very limited and obtaining a good quality comb (i.e. a comb with spectral lines oscillating in a perfectly synchronized manner) is a real challenge. In this project you will experiment a novel approach, pumping a nonlinear resonating device with a train of ultrafast sub-ps optical pulses (hence you will acquire a specific competence in ultrafast lasers). In particular you will investigate the potential degree of freedom given by this approach targeting the demonstration of a high-quality optical frequency combs. You will develop a significant understanding of the physics of nonlinear optical devices and also significant first-hand experience with ultrafast laser sources.

Dr Marco Peccianti

For more information on the projects listed below, please use the details provided on the supervisor's profile page.

Terahertz ultrafast science

Background:  The core interest of the Emergent Photonics Lab is Ultrafast Photonics with two major research lines in Terahertz Photonics and Complex Photonics. TIMING is a multidisciplinary project funded by the European Research Council (for a value of about 1.7 Million of GBP). It involves novel approaches to imaging and exotic nonlinear field-matter interactions, including processes that generate Terahertz waves. Key to the project success are elements directly inherited from the propagation in complex optical media. This project transversely intersects the kernel of our research interests. The outcomes are likely to have a key impact in several domains, from environmental detection to metrology, security, pharmaceutical manufacturing, medical and others. These MSc projects will complement our efforts in diagnostic technologies based on nonlinear field-matter interaction with ultrashort pulses. The candidate will gain access to the Emergent Photonics Laboratory (EPic) http://www.sussex.ac.uk/physics/epic/, a 110m^2 facility that comprises a very large spectrum of state-of-the-art photonic equipment (representing a total investment exceeding 1.1 Million of GBP from different funding sources):

-High energy ultrafast optical sources (5mJ@90fs Ppeak>50GW)

-Several types of ultrafast laser oscillators (Ti:Sa, Er-doped fiber oscillator, optical parametric oscillators)

-30m^2 of optical tables

-Two atomic-clock stabilised ultrafast optical combs

-Ultrafast microwave-on-optics diagnostics (i.e. generators, modulators and detectors)

-Ultrafast electronic acquisition systems (80GS/s with bandwidth >36GHz)

-Several diagnostic workbenches for terahertz, mid-Infrared and optical ultrashort pulses

-Terahertz imagers

-High Energy Terahertz sources

The project deploys within a fertile international collaboration of researchers. The successful candidate will join an interdisciplinary team.

Ultrafast Terahertz Imaging (Ref. MP1)

In this project, extremely short Terahertz pulses (ultrafast) will be used to produce a full 3-Dimensional electromagnetic image of an object, revealing its internal structure. This specific imaging approach is based on the Time-Domain Spectroscopy, a specific probing technique that does not have equivalent in other electromagnetic bands: the internal parts of an object are perceived exploiting delays between the generated electromagnetic echoes, in a method somewhat similar to ultrasound imaging. In this project you will acquire the necessary physical understanding of nonlinear field-matter interaction at the basis of the Terahertz generation detection. You will be part of the team that will design the imaging system and directly manage the generation from intense optical pulses. You will be also engaged in the reconstruction (electronic acquisition + software) of the electromagnetic 3D-image from the detected signals.

Mimetic material for the Terahertz domain (Ref. MP2)

In this research project we explore structures that can acquire specific Terahertz electromagnetic properties from a second object upon contact. In this research endeavour you will develop understanding on simulating plasmonic devices, i.e. electromagnetic structures that operates thanks to a coupling between photon and electrons. This project is led by the University of Sussex in collaboration with the INRS-EMT (Canada). As part of our research team you will design a Terahertz electromagnetic structure suited for the purpose that will be fabricated by our team. You will also test the devices in order to feedback the design process. Details on the specific targeted technologies and application will be discussed directly with you possibly under a non-disclosure agreement.

Dr Jose Verdu Galiana

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)

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)

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)

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)

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.