Supervisors

Supervisors

Prof Frank Vollmer, University of Exeter

Dr Charles Downing, University of Exeter

External collaborator: Prof Antonio Vidiella-Barranco, University of Campinas, Brazil

The University of Exeter is offering up to 9 fully funded doctoral studentships for September 2024 entry as part of our Doctoral Training Partnership with the EPSRC (Engineering, Physical Sciences Reserach Council).

The University of Exeter offers a world-class education and research in one of the most beautiful locations in the UK. As a Russell Group University our research makes a difference across the world and we’re committed to working with our PhD researchers to make the world greener, healthier, and fairer.  Our Doctoral College stimulates, supports and sustains a vibrant research and intellectual environment across and between disciplines for postgraduate and early career researchers. Focusing on investment and development in training, resources and facilities, we provide an outstanding quality experience for those in the early stages of their research careers.

The EPSRC is the main funding body for engineering and physical sciences research in the UK. The EPSRC's portfolio ranges from digital technologies to clean energy, manufacturing to mathematics, advanced materials to chemistry.

Competition details

The following project is one of eighteen being advertised as part of a competitive process for funding, there are a maximum of nine awards available.

Project Details

In this pioneering project, you'll harness the power of quantum optics to enhance the precision of biosensing. Prof Vollmer’s group specialises in utilising whispering gallery mode (WGM) microsphere sensors which are micron-scale interferometers (Figure a, b.) for the ultra-sensitive detection of single molecules, spanning diverse applications in biology and biochemistry from tracking neurotransmitter release to monitoring single enzyme activity1,2. This project seeks to fuse these cutting-edge sensors with quantum optical sensing techniques, enabling measurements with precision beyond classical limits and pushing the boundaries in optical biosensing. The challenge of single molecule detection using quantum optics remains open, promising unparalleled insights into molecular interactions and processes with unprecedented accuracy.

With our developed source of entangled photon pairs (Figure c.), originating from a nonlinear optical crystal PPKTP, you'll explore a well-established quantum sensing paradigm that leverages photon pairs for enhanced phase measurements within a Mach-Zehnder interferometer setup. Your task will involve optimising the photon pair source to generate narrow-spectrum photon pairs suitable for seamless integration with WGM microspheres via tapered optical fibres. Through quantum sensing experiments involving WGM microsphere sensors, including the exploration of a combined WGM resonator - Mach-Zehnder interferometer setup, you'll not only enhance sensing capabilities but also unveil other quantum optical phenomena associated with entangled photons in optical resonators, such as quantum interference (HOM interference). This primary aspect of the project offers abundant experimental avenues, from constructing experimental setups using free space and fibre optics to programming control systems and analysing data, all while employing single-photon detectors for highly sensitive light detection in controlled environments.

There is also an opportunity to work on the theoretical part of this project by doing quantum optics theory and simulations. We have initial results showing that a WGM resonator in the Mach-Zehnder interferometer with photon pairs at the input shows a dramatically different transmission spectrum compared with input classical light (Figure d.). This is the signal we propose to use for enhanced WGM sensing. There is a lot more to explore in the theory of photon pairs coupled to WGM resonators: you could work on developing the full model of the experiment in the Python package qutip, investigate other states of light such as squeezed states (used at the LIGO gravitational wave observatory), and make theory predictions to test directly in the experiment. The theory part of the project is supported by Dr Charles Downing3 and a collaboration with the group of Prof Antonio Vidiella-Barranco4 at the University of Campinas, Brazil. These new collaborations can be strengthened by additional EPSRC funding.
 

References

1 Yu, D. et al. Whispering-gallery-mode sensors for biological and physical sensing. Nature Reviews Methods Primers 1, 83 (2021). https://doi.org/10.1038/s43586-021-00079-2

2 Xavier, J., Yu, D., Jones, C., Zossimova, E. & Vollmer, F. Quantum nanophotonic and nanoplasmonic sensing: towards quantum optical bioscience laboratories on chip.  10, 1387-1435 (2021). https://doi.org/doi:10.1515/nanoph-2020-0593

3 Downing, C. A. & Vidiella-Barranco, A. Parametrically driving a quantum oscillator into exceptionality. Scientific Reports 13, 11004 (2023). https://doi.org/10.1038/s41598-023-37964-7

4 Sousa, E. H. S., Vidiella-Barranco, A. & Roversi, J. A. Generation and transfer of entangled states between two connected microtoroidal cavities: Analysis of different types of coupling. Optik 271, 170016 (2022). https://doi.org/https://doi.org/10.1016/j.ijleo.2022.170016

Figure a,b: Whispering-Gallery Mode (WGM) microsphere interferometer c: source of entangled photon pairs d: WGM interferometer with photon pairs at the input

Funding Information

For successful eligible applicants, the studentship comprises:

•     An index-linked stipend for up to 3.5 years full-time (currently £19,237 for 2024_25), pro-rata
      for part-time students.
•     Payment of University tuition fees
•     Research Training Support Grant (RTSG) of £5,000 over 3.5 years, or pro-rata for part-time
      students.

Fully-funded studentships are available for Home students.  A limited number (up to 30%) of UKRI fully-funded studentships are also available for applicants considered International for fee purposes.  Please see our DTP pages for more details

Equality, Diversity and Inclusivity

The University of Exeter is committed to promoting and supporting equality, diversity, and inclusion within our working environments and is at the heart of all our activities.  With over 27,000 students and 6,400 staff from 180 different countries, we offer a diverse and engaging environment where our diversity is celebrated and valued as a major strength. 

We actively encourage applicants with varied experiences and backgrounds and from all sections of the community regardless of age, race, ethnicity, sexual orientation, gender, religion, or disability status.  We are committed to creating an inclusive culture where all members of our community are supported to thrive.

Whilst all applicants will be judged on merit alone, we particularly welcome applications from groups currently underrepresented within our postgraduate research student community.  Reasonable adjustments are available for interviews and workspaces.

Entry requirements

Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology.  Applicants with a Lower Second Class degree will be considered if they also have a Masters degree or have significant relevant non-academic experience.

If English is not your first language you will need to meet the English language requirements and provide proof of proficiency. Click here for more information and a list of acceptable alternative tests.

How to apply

Apply now

To apply for this research project you will need to click on the 'Apply Now' button below.  Any applications submitted via other routes will not be considered for the studentship funding. 

In the application process you will be asked to upload several documents.  Please note our preferred format is PDF, each file named with your surname and the name of the document, eg. “Smith – CV.pdf”, “Smith – Cover Letter.pdf”, “Smith – Transcript.pdf”.

You will be asked to upload the following documents:

•     CV
•     A cover letter outlining your academic interests, prior research experience
      and reasons for wishing to undertake the project. 
•     Transcript(s) giving full details of subjects studied and grades/marks obtained.  This
      should be an interim transcript if you are still studying.
•     Two academic referees - see information below about references.
•     If you are not a national of a majority English-speaking country you will need to submit
      evidence of your proficiency in English (see entry requirements above)
   

Please see our dedicated DTP website for full details.

The closing date for applications is midnight (GMT) on Monday 6 May 2024.   

Reference Information

You will be asked to submit two references as part of the application process.  If you are not able to upload  your reference documents with your application please ensure you provide details of your referees.  If you provide contact details of referees only, we will not expect receipt of references until after the shortlisting stage. Your referees should not be from the prospective supervisory team.

If you are shortlisted for interview, please ensure that your two academic referees email their references to PGRApplicants@exeter.ac.uk, 7 days prior to the interview dates.  Please note that we will not be contacting referees to request references, you must arrange for them to be submitted to us by the deadline.

References should be submitted by your referees to us directly in the form of a letter. Referees must email their references to us from their institutional email accounts. We cannot accept references from personal/private email accounts, unless it is a scanned document on institutional headed paper and signed by the referee.

Contact Information

If you have any general enquiries about the application process please email PGRApplicants@exeter.ac.uk

If you have project specific enquiries please contact the lead supervisor named above.

Data Sharing

During the application process, the University may need to make certain disclosures of your personal data to third parties to be able to administer your application, carry out interviews and select candidates.  These are not limited to but may include disclosures to:

• the selection panel and/or management board or the equivalent of the relevant programme, which is likely to include staff from one or more other HEIs;
• administrative staff at one or more other HEIs participating in the relevant programme.

Such disclosures will always be kept to the minimum amount of personal data required for the specific purpose. Your sensitive personal data (relating to disability and race/ethnicity) will not be disclosed without your explicit consent.

Summary