UG Summer Studentships 2012
Summer Research Projects:
Undergraduate Bursaries 2012
In Summer 2012 we will be offering a number of bursaries of around £180 per week for up to eight weeks to support "returning" undergraduate students (all 2nd year students and 3rd year students undertaking an MSci degree) in undertaking research projects with members of academic staff and research groups in the School of Physics and Astronomy. This is a good way of experiencing what it is like to be a research student in an academic department and of contributing to a publishable piece of research.
If you are interested in applying for a bursary, please fill in the APPLICATION FORM and email it back to wendy.brennan@nottingham.ac.uk by Wednesday 1 February 2012 at 5pm.
The School's Postgraduate Committee will review the applications and we hope to be able to contact successful applicants as soon as possible. In order to maximise the number of bursaries that we can offer, we expect that some applicants will be asked to apply with their supervisors to the Nuffield Science Bursaries Undergraduate Research scheme (http://www.nuffieldfoundation.org/physics-undergraduate-bursaries which has a closing date of 20 February 2011. The Royal Astronomical Society (http://www.ras.org.uk/awards-and-grants/grants-for-studies) will also provide funding for undergraduate research bursaries this year) will also provide funding for undergraduate research bursaries this year
Research at the Australian Astronomical Observatory
Dr Steven Bamford (UoN) / Prof. Andrew Hopkins (AAO)
The Nottingham astronomy group has strong links with the Australian Astronomical Observatory. We are therefore keen to explore the possibility of sending an undergraduate student to Sydney to work on a joint research project. The summer student will work alongside researchers at the AAO, using data from the GAMA survey to study aspects of galaxy evolution. They will also gain experience of observing at the Anglo-Australian Telescope.
Interested students will be required to assist with the preparation of strong grant proposals to the RAS and AAO. The Sydney visit will be contingent on securing sufficient funding. In the event that funding is not forthcoming, a alternative scholarship to perform a GAMA-related research project in the Nottingham astronomy group will be offered.
NB: The idea for this scholarship project was generated by discussions with Gabriela Iacobuta, a 2nd year BSc student, who is very keen to do a summer internship at an astronomical observatory. I therefore believe she should receive first consideration for this scholarship. She will be applying for an AAO Student Fellowship in any case.
Electron spin resonance and Raman imaging of a hyperpolarised gas
Dr Michael J Barlow and Prof Peter Morris
The high nuclear spin polarisation of hyperpolarised 129Xe can be used to increase the detection sensitivity for a variety of NMR/MRI applications, including pulmonary imaging. Hyperpolarised xenon is produced via spin-exchange optical pumping (SEOP), a process whereby optically spin-polarised alkali metal electrons transfer spin polarisation to xenon nuclei via gas-phase collisions—resulting in a 104-105 increase in MR detection sensitivity. This process is still relatively poorly understood, especially since the introduction of high power, frequency narrowed lasers to pump the alkali metal spins. The main goals of this project are to characterise the SEOP process using (1) optically-detected electron spin resonance spectroscopy to explore the effects of different experimental parameters on the electron spin polarisation of the alkali metal vapour, and (2) ultralow-frequency Raman spectroscopy to determine how the massive amounts of energy being dumped into the system are being absorbed and dissipated by the ro-vibrational manifold of the nitrogen buffer gas. Additionally, low-field NMR spectroscopy and imaging of the hyperpolarised xenon will show how operating under these conditions affects the levels of xenon nuclear spin polarisation. The results of these studies should further shed light on the SEOP process, and influence the future methods of producing hyperpolarised noble gases.
Mean Field Dynamics of Ultracold Bosons in Artificial Gauge Fields
Keith Benedict
The effect of externally applied scalar potentials on the dynamics of ultracold bosons has been well studied, both experimentally and numerically. It has recently become possible to apply “artificial” gauge (i.e. generalized vector) potentials to such cold atom systems which can lead to much richer physics.
The simplest example of a gauge coupling is the interaction of a static magnetic field with a gas of charged particles leading to, for example, the quantum Hall efects. A more sophisticated type of gauge coupling arises from spin-orbit interactions in metals and semiconductors. Another situation of interest might be the interaction of quarks with a uniform color field in neutron stars. All of this systems are potentially amenable to simulations using ultra-cold atoms.
The aim of this project is to extend the standard method for the numerical solution of the mean-field (Gross-Pitaevskii) equation describing the dynamics of a Bose condensate to the situation in which there is more than one species of particle in the condensate and the condensate interacts with a static gauge field. The immediate objective will be to investigate flow instabilities in these systems in the presence of isolated impurities and optical lattices.
Students will need good computing skills and a good general background in theoretical physics such as might be provided by F33OT1, F33OT2 and F34SCO.
Adsorption of molecules on metal-supported graphene monolayers
Professor Peter Beton
The student will undertake a range of studies of the adsorption of molecules on graphene –terminated nickel and copper. The primary experimental tool will be scanning tunnelling microscopy and the student will work closely with a PhD student and a postdoc to acquire images of these surfaces with sub-molecular resolution. The objective will be to determine whether ordered arrays of organic molecules can form on graphene to provide a route to chemical and electronic, through doping, functionalization.
The molecules to be studied will deposited from solution and we will focus on perylene derivatives which have studied previously and are found to form extended arrays stabilised by hydrogen bonding. It is known that these molecules act as dopants for graphene and their assembly into regular structures at the surface provides a potential route to the formation of regular arrangements of dopants and the formation of periodic potentials. As substrates commercially available graphene on copper will be used and ina addition we will use graphene transferred from copper onto dielectric surfaces. An additional aim will be establish whether it is possible to acquire images of such films
Multi-variate connectivity assessment applied to MEG and EEG
Dr Matt Brookes and Prof Peter Morris
MEG is a new neuroimaging modality that enables assessment of electrical brain activity via measurement of magnetic fields induced by synchronous dendritic current flow. EEG measures the electrical fields at the scalp surface induced by the same current flow. EEG and MEG differ geometrically (electric and magnetic field patterns outside the head are spatially orthogonal and EEG is more sensitive to radially oriented and deep current sources). This means concurrent recordings offer greater information content.
We have recently developed novel multi-variate techniques to measure non-linear connectivity between spatially separate brain areas. These techniques have been applied to MEG data only, but could readily be extended to EEG, and concurrent EEG/MEG recordings combined using a novel technique developed in the lab by a previous summer student. In the combined case, significant advantages should be gained by improved signal to noise ratio and spatial specificity.
The goal of this studentship is to record concurrent MEG/EEG data (the feasibility of this has been previously demonstrated) and second to apply our multi-variate methodology to MEG data alone, EEG data alone and combined data. As time permits, a secondary goal would be to apply these same techniques to EEG data recorded inside an MRI system
How many galaxies are there in the universe?
Professor Chris Conselice
The universe has over a trillion galaxies in it, yet the true number is still uncertain. However, due to deep Hubble Space Telescope imaging, we are now able to see for a fraction of the universe all galaxies within a certain part of the sky. This can be used to derived both the total number of galaxies visible with current technology, and the total number of galaxies there are in the universe, by deriving the number we cannot see through simple calculations. This is a projected well suited for an undergraduate as it can be carried out in a relatively short period, and has a very broad applicability and interest.
Assessing kidney function with MRI
Dr Eleanor Cox and Dr Sue Francis
Magnetic resonance imaging (MRI) provides a method to quantitatively assess changes in tissues on assess changes in response to disease. Using different MR pulse sequences, MR images can be sensitised to measure flow or perfusion (phase contrast angiography and arterial spin labelling (ASL)) or diffusion. These measures may provide early markers of a disease. The project will involve applying these techniques to assess kidney function in patients with kidney disease. The project will be closely linked to an ongoing study in this area in the SPMMRC.
The main goal of the project will be the optimisation of MR pulse sequences, data acquisition of MRI data using the 3 Tesla scanner, and data analysis to study kidney function. The project requires some computational (Matlab) skills and mathematical skills. The research will be directly related to ongoing research in kidney function and MR developments at Nottingham.
Simulating STM images of C60 molecules
Janette Dunn
Scanning Tunnelling Microscopy (STM) can be used to obtain images of molecules with atomic resolution. It is important to be able to theoretically simulate the images expected from a given system in order to interpret the images being observed experimentally. This is usually done using Density Functional Theory (DFT), but such calculations can be computationally expensive, often taking a long time to run on a supercomputer (depending on the complexity of the system being modelled).
For the fullerene molecule C60, Hückel Molecular Orbital (HMO) Theory can be used as an alternative to DFT for obtaining simulated images of C60 molecules on various surface substrates. [1] In this project, the HMO approach will be used to treat charged anions of C60, where interactions with vibrations must be taken into account in addition to interactions with the surface.
The project will involve use of the symbolic computation software Mathematica, although no prior knowledge of Mathematica will be assumed.
[1] ID Hands, JL Dunn and CA Bates, Phys Rev B 81, 205440 (2010)
Non-equilibrium quantum dynamics
Professor Juan P Garrahan
Real quantum systems are "open" in the sense that they interact with their environment (be it a thermal bath, or a larger quantum system). This leads to an irreversible loss of coherence and to energy dissipation. As understanding of the role of a system’s environment has improved it has been possible to observe quantum behaviour in ever larger systems including optical cavities, electrical circuits and, very recently, even in a hybrid device combining an electrical circuit with a mechanical oscillator. Many of the important current questions in quantum dynamics relate directly or indirectly to the problem of quantum dissipation.
The last couple of decades have also seen a lot of progress in our understanding of classical (i.e. non-quantum) non-equilibrium systems. Much less is understood of quantum non-equilibrium dynamics. This project is about trying to use the tools and concepts of classical non-equilibrium physics to explain properties of quantum non-equilibrium systems. It will be about studying via numerical simulations the dynamics of simple models of open quantum systems. A central aim is to understand the role of dynamical fluctuations and the possible existence of dynamical phase transitions analogous to those observed recently in classical non-equilibrium systems. The project will be closely aligned to our ongoing research in this area.
This is a theoretical/computational project. A good grasp of quantum mechanics is required. Some computational
Characterization Cs atoms in an optical dipole trap
Lucia Hackermueller
The development of laser cooling techniques has led to a rapid growth of the field of ultracold atoms. In many laboratories around the world, gaseous samples of hundreds to billions of (mostly alkali) atoms are routinely cooled to micro- and nanokelvin temperatures. At these record low temperatures, quantum phenomena are important and can be directly observed. Experiments today cover very different areas of physics, ranging from fundamental problems in condensed matter physics to applications in sensing and precision metrology.
Cs atoms out of dipensors are cooled and trapped using a magneto-optical trap (MOT). In this setup we can reach temperatures down to 100 microkelvin. In order to go to even lower temperatures an additional cooling step has to be applied, which is evaporative cooling in an optical dipole trap. The potential of a tightly focussed laser beam can be used as a trap for the atoms. By selectively removing the hottest atoms out of the trap and allowing re-thermalisation, we lower the mean temperature of the ensemble down to nanokelvin. This cooling procedure is analogues to blowing onto a cup of tea and in this way removing the hottest molecules. With this method we will finally observe Bose-Einstein-Condensation of the atomic sample. During the project the efficiency of transferring atoms from the MOT to the dipole trap will be measured depending on the temperature, the initial atom number, the trap depth of the optical trap and the interaction between the atoms. The student will also help to build small but important parts of the experiment like beam shutters, safety circuits, photodiodes and set up optical components.
Light sheet detector for ultracold quantum gases
Peter Krüger
The development of laser cooling techniques has led to a rapid growth of the field of ultracold atoms. In many laboratories around the world, gaseous samples of hundreds to billions of (mostly alkali) atoms are routinely cooled to micro- and nanokelvin temperatures. At these record low temperatures, quantum phenomena are important and can be directly observed. Experiments today cover very different areas of physics, ranging from fundamental problems in condensed matter physics to applications in sensing and precision metrology.
A crucial ingredient in every cold atom experiment is a detection system. In the course of this project, the students will develop an optical imaging system, capable of directly visualising quantum phenomena, such as Bose-Einstein condensation and matterwave interference, onto a CCD. The geometry of the detector will be a flat thin sheet of laser light that can be produced by cylindrical lenses. Ultracold rubidium atoms will be released in a controlled way from an existing magnetic trap, so that they fall through the light sheet under the influence of gravity. The fluorescence occurring upon passage through the sheet of even a single atom is detectable with a modern high-end CCD camera.
Exactly solvable spin models for quantum magnetism
Igor Lesanovsky
Many-body quantum systems often exhibit new and unexpected physics. This is related to the fact that microscopic degrees of freedom can couple in such a way that they spontaneously show a pronounced collective behaviour. In a magnet for instance, microscopically small magnetic moments align to produce a macroscopic magnetic field.
A lot of understanding of this and related effects stems from the analysis of so-called spin models where magnetic moments are regarded as interacting two-level systems. In general these models – albeit simple looking – are very difficult to solve.
Here at Nottingham we have recently identified a new class of exactly solvable models some of which you are going to explore in the course of the summer project. You will learn how to formulate a quantum mechanical many-body problem and how to find and analyse the ground state of certain spin models.
This challenging project requires good mathematical skills, some computational skills and some knowledge of quantum mechanics. The results might be directly applicable for ongoing theoretical research in the fields of condensed matter physics and quantum information as well as for experiments with ultra cold atoms conducted here at Nottingham.
Brown and white fat measurements in infants using MRI and MRS
Kathryn Murray (with Penny Gowland and Caroline Hoad)
Magnetic resonance (MR) imaging and spectroscopy are very useful in study physiology and changes that occur in disease, including the ratio of subcutaneous to visceral adipose tissue, and the ratio of brown fat to white fat, which are important measures in studying human metabolism and the effects of obesity and diabetes.
MR fat signals are distinguished from water by the large chemical shifts of the dominant methylene group and short relaxation times. mDixon methods use signal coherences arising from this frequency shift for water-fat fraction imaging by taking measurements at different echo times [1][2].
This project aims to measure brown and white fat volumes in adults and infants. Students will be involved in (i) data collection on the 1.5T scanner, and (ii) data and image processing to analyze the ratio of volumes of brown fat to white fat. Some Matlab programming may be required to investigate and optimize methods for separating the two fat signals.
1. Eggers, H., et al., Dual-echo Dixon imaging with flexible choice of echo times. Magnetic Resonance in Medicine, 2011. 65(1): p. 96-107.
2. Hu, H.H., K.S. Nayak, and M.I. Goran, Assessment of abdominal adipose tissue and organ fat content by magnetic resonance imaging. Obesity Reviews, 2011. 12(501): p. e504-e515.
The self-organisation of gold nanoparticles on surfaces by electrospray deposition in vacuum
Dr James O'Shea & Prof Philip Moriarty
A fundamental goal of nanoscale science is the development of protocols to control the interactions, and thereby the ordering, of nanoparticles on solid substrates with a range of applications from catalysis to molecular electronics. Gold, for example is pretty inert, but gold nanoparticles are catalytically active for the oxidation of carbon monoxide. Gold is of course also a great electrical conductor and the formation of networks of nanowires on surfaces has applications in contacting functional single molecule devices on surfaces. Networks of gold nanowires, or ‘nanofoams’ can be self-organised on surfaces by the rapid dewetting of a suspension or solution of colloidal gold nanoparticles e.g. O’Shea et al, APL 81, 5039 (2002). This has been achieved by spin-coating under ambient conditions, generating cellular networks with lengthscales on the order of 100nm. However preliminary results from depositions of wet molecules by electrospray in vacuum suggest that such an extreme environment can generate nanostructures on much smaller lengthscales. The goal of this project is to form conducting gold networks small enough to contact individual functional molecules such as single molecule magnets and photovoltaic dyes on oxide surfaces. You will have a dedicated vacuum-based electrospray deposition system and use atomic force microscopy to characterise the networks of gold nanoparticles formed.
Dispersion driven morphology in thin film multi-layers
James Sharp
This project will study the patterns that form in multi-layers of polystyrene (PS) and aluminium (Al) when the individual layer thickness values are ~100nm. When Al/PS/Al tri-layers are heated, the dispersion forces that act between the Al layers act to pull them into contact. However, the intervening polystyrene layer must flow in order for this to happen. A competition between dispersion driven interactions, flow in the PS layer and bending of the Al layers results in the surface of the samples wrinkling with a characteristic wavelength which acts a compromise between these competing effects (figure 1).
The length scales associated with the wrinkle formation occur on the 1-100 micron length scale and can be studied using an optical microscope. The length scales are sensitive to the thickness of the individual PS and Al layers. Simple measurements of the length scale as a function of the thickness of the layers can be used to determine the Hamaker constant for this system which is a measure of the strength of the interatomic interactions between the aluminium atoms. You will develop a set of experiments and a simple theory to study this phenomenon.