Optical forces in skyrmionic beams

Optical forces in skyrmionic beams

A world-class environment for your research degree

The School of Physics is offering a portfolio of PhD Scholarships across all its world-class research groups. These prestigious Scholarships represent a great opportunity to start your Postgraduate Research Career working with world-class academics in a supportive training and development environment. Physics at Bristol was ranked 5^th for Research in the 2022 Research Excellence Framework (REF) results, and the University of Bristol is truly world-leading: 55^th in the QS World University Ranking (2024) and 81^st in the Times Higher Ranking (2024).

What does a Scholarship cover?

For home students, the scholarships will cover living expenses (UKRI rate), University tuition fees (see PhD Physics Study at Bristol University of Bristol), and training and support expenses. We also welcome applications from outstanding international candidates: we are able to offer a very small number of fully-funded places, but also accept students who can provide full or partial funding from other sources. If you need an offer letter to apply for a competitive scholarship, please get in contact with us well before any deadlines.

Research Project

The invention of optical tweezers was recognised in the 2018 Nobel prize for physics. With optical tweezers, focused lasers push, pull, twist and otherwise deform matter on a microscopic scale. Optical skyrmions are a more recent discovery, consisting of topologically protected polarisation states that can interact with the angular momenta of trapped particles. Researchers are just beginning to experiment with such beams for optical trapping due to the complex interactions that they offer [Shen et al, Nature Photonics, 2024]. The polarisation gradients present offer a unique opportunity to probe the so-called Belinfante curl contribution to the spin-optical angular momentum. Recent calculations have demonstrated complex orbital motion of absorbing particles in such beams, including spin contributions with constantly shifting axis of rotation [O’Donnell and Hanna, Proc. SPIE, 2024]. The aim of the present project will be to extend calculations to clusters of particles and, in particular, flexible systems. This will offer the opportunity to probe our understanding of the fundamental processes underlying optical forces, including the so-called Abraham-Minkowski controversy over the nature of optical momentum in a medium. The project will make extensive use of the University’s supercomputing facilities, and will involve collaboration with experimental groups at the Beckman Laser Institute (California).

Members of the Theory group will be able to give pastoral support and advice; Skyrmions are ubiquitous in condensed matter physics and theory group members will also be able to offer support in this field and in computational aspects. Members of the Quantum and Soft Matter group are also experienced with optical tweezers and optical forces.

The Bristol Physics Graduate Research Community

If successful, you will become a member of the Physics Graduate School, a vibrant and diverse community of 200-plus research students from a wide range of countries and backgrounds. The Graduate School:

·        runs a comprehensive induction programme to get you off to the best possible start in your research, and a rolling programme of targeted skills training on writing, presenting, project-planning, etc.

·        operates a “one-stop shop” approach to help you navigate through the University procedures

·        organises meetings for postgraduate opportunities, and support in transitioning to post-PhD careers

·        connects you to the wider University, including the Bristol Doctoral College, www.bristol.ac.uk/doctoral-college/.

How do I apply?

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).

Please note that a research statement is not a requirement from the School of Physics, however as it is a system requirement you are encouraged to specify a research theme and a list of your preferred academic supervisors.

Please contact the academics within the School of Physics research areas for information.

Applicants will be assessed on merit, and interviews will be held for shortlisted applicants.

You need to apply through the University of Bristol application system at http://www.bristol.ac.uk/study/postgraduate/apply/. Please select Physics PhD or Physics MSc by Research on the Programme Choice page. The School of Physics supports Diversity and Equality, and we invite all eligible candidates to apply. We encourage applications from under-represented groups. We hold a Bronze Athena Swan award and a Physics Juno Champion award.

Please specify “Bristol Physics Research Scholarships” on the application form as your source of potential funding. Early application is encouraged. The closing date for applications to this call is 15 January 2025.

What are the candidate requirements?

A first degree in physics 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 Bristol Physics Graduate School at: physics-pg@bristol.ac.uk