Start date: 1 October 2018
Swansea University is proud to offer 15 fully-funded PhD scholarships for students commencing study in October 2018 or January 2019.
The scholarships will be awarded on the basis of student excellence across a portfolio of 34 potential projects.
Swansea University is a UK top 30 institution for research excellence (Research Excellence Framework 2014) and has been named Welsh University of the Year 2017 by the Times and Sunday Times Good University Guide.
Applications are invited for a fully funded PhD studentship in Physics.
The sensitivity of any measurement will be limited by noise, ultimately at the quantum level. In some cases, one can use quantum mechanics cleverly to reach higher sensitivity than classical physics allows, opening up the possibility of extraordinarily sensitive measurements of e.g. magnetic fields; something of relevance broadly, for instance in technology and medicine. In this project we will investigate the sensitivity of trapped ultracold atoms and their coupling to photons in a nanoscale optical fibre to the external environment. The aim is to explore the nonlinear response of the atoms when the trapped sample is optically very dense and to investigate how this response could be used to improve the sensitivity beyond limits set by classical noise. Ultimately, results will guide development of quantum technology on the quantum metrology frontier.
The project will utilise our laser cooling and trapping facility to create temperatures of around, or even below, 1 micro-Kelvin, leading to pure samples with controllable quantum states. Our trapping apparatus incorporates a tapered optical nanofibre. Such fibres are made by heating and stretching standard optical fibres much like ones used in optical fibre communications networks. In this fabrication process a short segment (a few centimetres) becomes thinner than the wavelength of the photons that propagate in the fibre. In this thin segment a large fraction of the intensity of the photon, whilst still guided by the fibre, exists outside the fibre. We have constructed the experimental apparatus so that the nano-segment coincides with the trapped ultracold atoms. Now, if the atoms are controlled so that they are trapped within the extent of the electric field of the fibre photon, an interaction may occur. This interaction has already been observed in our setup and we are now progressing to detailed studies.
The key feature of the nanofibre photon is that the extent of the electric field (the “size” of the photon) is commensurate with the resonant cross section of the atom. In practice this means that the probability of the interaction is very high, and if the sample is also very dense the nonlinear response of the atom will also be high. This nonlinearity will be key in manipulating the quantum state of the fibre photon.
A favourable technical feature of the nanofibre is that the pigtails at both ends are compatible with standard fibre photonics allowing the use of standard components such as fibre couplers and single-photon counting modules. Our apparatus is also very compact which ultimately leads to portability of the technology.
Find out more about experiments on quantum physics with ultracold atoms at Swansea University.
Training associated with the project work leads to transferrable skills in areas critical to the advancement of quantum technologies such as atom trapping, photonics, ultra-high vacuum technology, lasers, and computer modelling via simulations and 3D CAD design.
Supervisors/ Academic contacts: Dr Stefan Eriksson and Professor Michael Charlton
The successful applicant will have access to our Postgraduate Research Student Training programmes.
Applicants should have (or expect to obtain) a first class honours degree (or equivalent) and/or a distinction at master's level in physics.
Laboratory experience in a relevant area of physics such as lasers or optics is desirable but not essential.
Due to funding restrictions, this scholarship is available to UK/EU students only.
The scholarship covers the full cost of UK/EU tuition fees, plus an annual stipend of £14,553 (in line with the RCUK stipend amount) for 3 years.
There will also be £1,000 per annum available for research expenses such as travel, accommodation, field trips and conference attendance.
Please visit our website for more information.