QD Squeezed Light for fibre-based invisible range-finding

QD Squeezed Light for fibre-based invisible range-finding

Are you interested in doing a PhD in the burgeoning field of quantum technologies? This project, ‘QD Squeezed Light for fibre-based invisible range-finding’ is part of five fully-funded studentships available across a number of potential research areas within University of Bristol’s Quantum Engineering Technology Labs (QET Labs), to commence September/October 2024. To view the additional PhD projects available and apply, please visit the QET Labs website via this link.

Project description

In the QD group we have recently developed a technique to modulate low intensity coherent light deterministically using a single quantum dot (QD). We have achieved a phase modulation of the light induced by a spin precessing in a magnetic field (accepted in Phys Rev Rep). Although we do not yet have a robust theoretical description of the light state, we believe the photons are entangled with the spin, and moreover the light state is likely to be squeezed. This PhD project proposes to explore whether the state of QD-scattered light is squeezed, and explore potential applications. One important advantage of photons from QD photonic devices is their brightness: we have already demonstrated that even at such low intensities, we obtain enough photons within a 10micro-second window to analyse the phase on a 10us timescale. We would like to explore whether these states could be used in applications that accurately detect vibrations in optical fibre (on a millisecond timescale). One application could be in earthquake detection: the existing telecommunications network could be used to detect a “common mode” vibration across a network which would be sensitive to long-distance vibrations without picking up local acoustic noise. Because of the single photon level of the light used, and the fact that one could easily switch between different QDs to vary the wavelength, one could employ invisible range-finding techniques. This PhD project could be either mainly experimental or mainly theoretical, depending on the inclination of the candidate. A theoretical PhD would focus on a robust theoretical quantum optical description of the scattered state including the squeezing, and explore theoretical protocols for sensing. An experimentally focused project would involve measuring the level of squeezing and exploring the sensitivity to acoustic vibrations when the light is input into a fibre. In the case where there is no squeezing we still believe the narrowband scattered light states should provide a sensitive probe of fibre vibrations.

To apply for this project, or any of the other projects available within QET Labs, please use our online application form, and select “Physics (PhD)” as the programme. You will need (1) a CV, (2) a Personal Statement, which is a one- to two-page document introducing yourself and outlining your motivation for PhD research, and (3) a transcript of any qualifying degrees (completed and/or underway). Whilst a research proposal is not required by the School of Physics, it is a required document on the application portal and therefore a blank document can be uploaded instead. We strongly encourage applications from home candidates and candidates from underrepresented groups. At the top of your personal statement, please state clearly that you are applying for a PhD within the Quantum Engineering Technology Labs, and state which of the PhD projects you are interested in. QET Labs supports Diversity and Equality, and we invite all eligible candidates to apply. We encourage applications from under-represented groups. Within the School of Physics, we hold a Silver Athena Swan award and a Physics Juno Champion award.

Early application is encouraged. The closing date for applications to this call is midnight Monday 3rd June.

QETLabs: A world-class research environment

The Quantum Engineering Technology Labs has the broad remit of accelerating application of quantum technologies, developing new capabilities and hardware that use quantum phenomena, and to explore fundamental quantum information science with new technology. QET Labs benefits from state-of-the-art facilities, including fully equipped quantum optics laboratories in the School of Electrical, Electronic and Mechanical Engineering and the School of Physics, integrated quantum photonics characterisation suites, ultra-low vibration noise facilities in the Nanoscience and Quantum Information building and device nano-fabrication in the University cleanroom.

Physics at Bristol was ranked 5th for Research in the 2022 Research Excellence Framework (REF) results, and the University of Bristol is truly world-leading: 55th in the QS World University Ranking (2024) and 81st in the Times Higher Ranking (2024).

What does a Scholarship cover?

For successful students, the scholarships will cover living expenses (UKRI rate), University tuition fees (see PhD Physics Study at Bristol University of Bristol) and consumables.

The Bristol Graduate Research Community

If successful, you will become a member of either the Physics or Engineering Graduate School, vibrant and diverse communities of 200-plus research students from a wide range of countries and backgrounds. The Graduate Schools run comprehensive induction programmes to get you off to the best possible start in your research, and rolling programmes of targeted skills training in writing, presenting, project-planning, etc. The Schools operate a “one-stop shop” approach to help you navigate through the University procedures, organise meetings for postgraduate opportunities and support in transitioning to post-PhD careers, connecting you to the wider University, including the Bristol Doctoral College, www.bristol.ac.uk/doctoral-college/.

What are the candidate requirements?

A first degree in physics, engineering, chemistry, computer science, or a related subject, normally at a level equivalent to at least UK upper second-class honours, or a relevant postgraduate master’s qualification. Please see Applying from your country International students University of Bristol on the International Office website.

English language requirements

If English is not your first language, you need to meet English Language Profile F. Further information about this can be found here: English language requirements Study at Bristol University of Bristol

Admissions Statement: https://bristol.ac.uk/study/media/postgraduate/admissions-statements/2023/phd-physics.pdf

Contacts and further information

Please contact the QET Labs enquiries mailbox (qetlabs-enquiries@bristol.ac.uk).