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Durham University

Quantum Light and Matter

PhD positions available for October 2021

Please click on the links in the table for more information on each project listed. More projects may be added as they become available.

Projects offered: Supervisor(s)

Laser-cooling molecules for quantum simulation

Dr. Hannah Williams & Prof. Simon Cornish

Atomic Clock Array for Quantum Measurement

Prof. M. P. A. Jones and Prof. C. S. Adams

Magneto-optical spectroscopy

Prof. Ifan Huges

Continuous time Quantum Computing

Dr. Nicholas Chancellor and Dr. Viv Kendon

A Quantum Gas Microscope for Polar molecules

Prof. Simon Cornish & Dr. Hannah Williams

Quantum Simulation with Ultracold RbCs Molecules

Prof. Simon Cornish & Prof. Simon Gardiner

Quantum degenerate mixtures of Cs and Yb: quantum droplets and ultracold molecules

Prof. Simon Cornish & Prof. Simon Gardiner

Theory of Ultracold Molecules

Prof. Jeremy M. Hutson
Nanotomics: atom-light quantum optics at the nanoscale Prof. C. S. Adams
Rydberg quantum optics Prof. C. S. Adams
Searching for a Fifth Force with Ultracold H Atoms Dr. D. Carty and Prof. M. P. A. Jones
Designing quantum technology using Rydberg atoms, cold molecules, and Bose-Einstein condensates Dr Viv Kendon or Dr Robert Potvliege or Prof. Simon Gardiner
Simultons in atomic vapours Dr Robert Potvliege and Dr Steven Wrathmall



Laser-cooling molecules for quantum simulation

Project Video here

Supervisors: Dr Hannah Williams, Prof. Simon Cornish

This is a new project which will apply laser cooling techniques directly to molecules. The experimental setup will consist of a cryogenic buffer gas source, producing a beam of molecules, which will then be decelerated via laser cooling in order to be trapped in a magneto-optical trap. The aim of the experiment is to capture single molecules in micromagnetic traps and to control both the internal states of the molecules and the interactions between them. One of the biggest challenges will be to have a high enough number of molecules, at sufficiently low temperatures, to efficiently load individual traps. To achieve this we will implement and optimise state-of-the-art cooling and trapping techniques. A successful PhD candidate can expect to learn skills in the design, construction and running of a complex AMO physics experiment. They will develop expertise in the control of ultracold molecules, and contribute to the advancement of the field. In addition they will have the opportunity to become involved in collaborations and present their work at international conferences.


Atomic Clock Array for Quantum Measurement

Supervisor: Prof. M. P. A. Jones and Prof. C. S. Adams

The goal of this project is to create a new type of atomic clock based on an array of individual strontium atoms. The atoms form an artificial crystal held in place using light beams, with energy levels in each atom acting as a highly precise atomic clock. By using additional highly excited Rydberg energy levels, the atoms can be made to interact, leading to the formation of quantum correlations known as entanglement, that can be exploited to enhance the precision of the clock, or even for quantum computing. The project builds on original theoretical and experimental work in Durham, and exploits our existing state-of-the-art apparatus for trapping individual Sr atoms (image shows a picture of single, trapped strontium atom in our laboratory) and exciting them to Rydberg states.

Video: https://www.youtube.com/watch?v=5zrUIwAgA_U

Contact: m.p.a.jones@durham.ac.uk or c.s.adams@durham.ac.uk

Magneto-optical spectroscopy


Supervisor: Prof. Ifan G Hughes.
In our laboratories we study quantum mechanics using the toolbox of atoms, lasers and magnets. We perform experiments with atomic vapours, and model the results with our in-house developed code ElecSus. Topics studied have spanned fundamental through to the applied. At the fundamental level we exploit the mysterious quantum property of entanglement to realise single-photon sources, and study light propagation in media characterised by non-hermitian degeneracies. We also take advantage of our expertise to characterise the optical properties of the medium to develop novel optical devices, such as optical isolators and the narrowest atomic filters realized to date – these find applications in solar studies and predictions of space weather.

Link to video https://www.youtube.com/watch?v=wRXSWgUO8lc


Continuous time Quantum Computing

Supervisor(s): Nicholas Chancellor (1st), Viv Kendon (2nd)

Quantum computing can be divided into two categories, gate model where
computation is done using discrete "gate" operations similar to those
used in classical computers, and continuous-time, where problems are
directly mapped to quantum hardware and the continuous rotations which
make up natural quantum evolution solve the problem. The goal of this
project is to understand continuous-time computation on two fronts,
how the physics of these systems solve problems in simple settings,
and how new methods can be developed to use the physics of these
systems algorithmically.

Project Video
https://www.youtube.com/watch?v=HMxAuR3IGtA
http://nicholas-chancellor.me/
https://kendon.info/viv/

Microscope Vacuum Chamber


Quantum Gas Microscope for Polar molecules

Prof. Simon Cornish & Dr. Hannah Williams

Video: https://youtu.be/ODKDb4igpDI

Quantum gas microscopy is a powerful new tool used to image single atoms on the individual sites of an optical lattice. Such experiments enable the quantum simulation of lattice-spin models which are ubiquitous in condensed matter physics. However, to date these experiments have been largely limited to only the short-range interactions available to ground state atoms. One solution to this is to use polar molecules in place of atoms in the lattice, which may then interact over long-range via the dipole-dipole interaction.

The most effective method of producing ultracold molecules so far is to bind together ultracold atoms produced using standard laser cooling techniques. This has been successfully demonstrated in our group for the bialkali RbCs molecule.

In this project, you will help develop a next-generation apparatus to perform quantum gas microscopy of ultracold molecules confined to an optical lattice. Key milestones of the PhD project will include the production and optical trapping of quantum-degenerate gases of alkali atoms, association of atoms to form ground-state molecules, and high-resolution imaging of atoms and molecules in an optical lattice. This project forms part of an ongoing collaboration between Durham University, Imperial College London, and the University of Oxford focussed on “Quantum Science with Ultracold Molecules”.


Quantum Simulation with Ultracold RbCs Molecules

Supervisors: Prof. Simon Cornish, Prof. Simon Gardiner

Ultracold polar molecules offer an exciting new platform for quantum science experiments exploring many-body physics. This PhD project will make use of a state-of-the-art apparatus capable of producing a gas of 4000 ground-state RbCs molecules at microkelvin temperatures. The apparatus works by binding together atoms from an ultracold mixture of Rubidium (Rb) and Caesium (Cs) to form the molecules. This is achieved fully coherently by first sweeping a magnetic field through a Feshbach resonance to form weakly-bound molecules, and then transferring these to deeply bound states by stimulated Raman adiabatic passage.

The project will focus on controlling the internal and external degrees of freedom of the molecules. The internal state can be fully controlled with microwaves whilst optical lattices, traps made from a standing wave of light, can be used to confine the molecules spatially. You will lead experiments that use the rotational states of the molecule as a synthetic dimension for quantum simulation. Later in the project, you will transfer the developed expertise in internal state control to a new apparatus where single molecules will be confined to individual tweezer traps to form a reconfigurable array. This will enable the study of prototype quantum gate operations and lattice-spin models across small arrays of molecules. This project forms part of an ongoing collaboration between Durham University, Imperial College London, and the University of Oxford focussed on “Quantum Science with Ultracold Molecules”.

Video: coming…

CsYb Vaccum Chamber


Quantum degenerate mixtures of Cs and Yb: quantum droplets and ultracold molecules

Prof. Simon Cornish & Prof. Simon Gardiner

The Cs-Yb project is unique in combining two atomic species with very different properties. This leads to a rich experimental platform, with many potential research directions. Your research project will focus on two related themes:

1. The study of quantum degenerate atomic gas mixtures. Here we exploit the range of Yb isotopes, both bosonic and fermionic, together with the ability to tune the Cs-Cs interactions using a Feshbach resonance to probe a variety of phenomena, including beyond mean-field physics through the formation of heteronuclear quantum droplets.

2. The creation of ultracold CsYb molecules for quantum simulation. Such molecules have a doublet-sigma symmetry in the ground state, resulting in both a magnetic and an electric dipole moment. This leads to richer physics, particularly in optical lattices where CsYb molecules could be used to simulate quantum spin models.

Your project will use an existing state-of-the-art apparatus and will build upon our recent production of the first quantum degenerate mixtures of Cs and Yb. The next phase of the experiment is to explore the dynamics of this novel quantum gas mixture, in both species-specific potentials and optical lattices. In turn, these developments will enhance the prospects of molecule formation using an interspecies Feshbach resonance.

Video: https://youtu.be/yZzybsP5AWA


Theory of Ultracold Molecules

Prof. Jeremy M. Hutson

Ultracold molecules provide an exciting new platform for quantum science. They may be created either by associating pairs of ultracold atoms or by cooling existing molecules, most commonly by laser-cooling. We develop the theory needed to create ultracold molecules and understand their properties. We have particular expertise in atomic and molecular collisions. We work with the best experimental groups around the world, including in Durham, to interpret experiments, suggest new ones, and develop ideas for future directions for the field.

The newest horizon is to create configurable arrays of ultracold molecules in optical tweezers; each tweezer holds a molecule in space at the waist of a focussed laser beam, and the molecules can be moved around to make different shapes of array with different quantum properties. You will work to understand the properties of molecules in tweezers, and how full quantum control may be achieved with applied electric, magnetic and polarised laser fields.

Our goal is to implement quantum gates based on ultracold molecules, which can form building blocks for quantum simulators and quantum computers. This will lead to applications in quantum science and establish ultracold molecules as a new platform for quantum technology.

Further information on the research group is available at
http://community.dur.ac.uk/j.m.hutson
and on our research projects at
http://community.dur.ac.uk/j.m.hutson/studentship-info-2020.pdf

Contact: J.M.Hutson@durham.ac.uk


Nanotomics: atom-light quantum optics at the nanoscale

Supervisor: Prof. Charles Adams

In collaboration with Prof. Vahid Sandoghdar (Director at the Max Planck Institute for the Science of Light) we are investigating atom-light interactions at the nanoscale using both high numerical aperture focusing and strong confinement of atomic ensembles (see figure which shows an atomic vapour cell with nanoscale structures written into the glass). This technology has the potential for applications in nanoscale sensing and quantum devices.

This studentship is funded by the Max Planck Institute for the Science of Light.

Contact: c.s.adams@durham.ac.uk


Rydberg quantum optics

Supervisor: Prof. Charles Adams

Highly-excited Rydberg atoms provide the only known medium with sufficiently strong photon-photon interactions to realise all-optical quantum gates. In this project we will investigate quantum interfaces using Rydberg excitations (see figure) to control individual photons creating the basic building blocks for quantum networking of quantum computers.

Contact: c.s.adams@durham.ac.uk


Searching for a Fifth Force with Ultracold H Atoms

Supervisor: Dr. David Carty & Prof. M. Jones

It is conventionally accepted that there are four fundamental forces in nature: gravitational, electromagnetic, strong nuclear and weak nuclear forces. However, the existence of dark matter and dark energy have led many to postulate a “fifth” force that acts over a range anywhere from nanometres to cosmological distances.

In this PhD project, you will develop a source of ultracold (μK) hydrogen or deuterium atoms that you will use for making precision spectroscopic measurements of Rydberg states that may reveal a fifth force acting on atomic length scales. Such a force would be carried by a new dark-matter boson with rest mass on the order of eV to keV.

Key milestones of the PhD project will be to create an intense H-atom (or D-atom) beam that can be slowed using our moving-trap Zeeman decelerator (MTZD, see figure). Atoms will be loaded into a novel magnetic trap magneto-optical trap (MT-MOT) along with laser coolable atoms (e.g. 7Li), which were co-decelerated into the MT-MOT by the MTZD. The 7Li will be laser cooled to μK temperatures and the H/D atoms will be sympathetically cooled via controlled collisions with the 7Li.

H/D atoms will be formed into a fountain for precision measurement of the Rydberg series up to n~100. A deviation from Coulomb’s law between the electron and the proton/deuteron will be indicative of a fifth force. The measurement will also yield an ultraprecise value of the Rydberg constant and the radius of the proton/deuteron.

Funding: An EPSRC DTP would support this studentship.

Contact: david.carty@durham.ac.uk


Designing quantum technology using Rydberg atoms, cold molecules, and Bose-Einstein condensates

Supervisor: Dr Viv Kendon, or Dr Robert Potvliege, or Prof. Simon Gardiner

The theorists in QLM work closely with the experimentalists to develop the ways to test and apply their experimental systems. In Durham we have experiments involving Rydberg atoms, and cold atoms and molecules that are very promising for many quantum technology applications. These include metrology and sensing, and prototype quantum computers, especially for quantum simulation of quantum many body systems. For example, we are interested in unconventional ways to compute, including using the natural Hamiltonians of the quantum systems to encode computations that are solved in continuous-time rather than using discrete gate operations, and in next-generation atom-based interferometric rotational and electromagnetic field sensors. The necessary theory will be taught in a series of graduate lectures in the first six months of the PhD, and a combination of analytical and computational methods will be used to develop the ideas and models. Although there is a particular need for experimental PhD students this year, if interested in such a theoretical project, please do enquire with Dr Viv Kendon, Dr Robert Potvliege, or Prof. Simon Gardiner.

Contact: viv.kendon@durham.ac.uk or r.m.potvliege@durham.ac.uk or s.a.gardiner@durham.ac.uk