Electrically Switchable Ferromagnetic Josephson Junctions

PGR-P-868

Key facts

Type of research degree: PhD
Application deadline: Ongoing deadline
Project start date: Wednesday 1 October 2025
Country eligibility: International (open to all nationalities, including the UK)
Funding: Competition funded
Supervisors: Professor Gavin Burnell
Schools: School of Physics and Astronomy
Research groups/institutes: Condensed Matter

<h2 class="heading hide-accessible">Summary</h2>

This experimental project in superconducting spintronics will study spin-torques in ferromagnetic superconducting Josephson Junctions. Superconducting computers operating at 4.2K have been proposed to solve the problems of energy usage by large-scale computing, as components for a neuromorphic computer and to interface between a quantum computer operator at millikelvin temperatures and conventional room temperature electronics. Whilst the technology to implement logic in such a 4.2K computer is well established, there remains, as yet, no suitable technology to implement cryogenic memory beyond registers. This project aims to address this need by developing the physics and materials to implement memory technologies based on ferromagnetic Josephson junctions.

<h2 class="heading hide-accessible">Full description</h2>

A ferromagnetic Josephson junction based memory combines the magnetic storage capabilities of a conventional magneto-resistive RAM cell with the dissipation- less nature of a superconductors. As with the first generation of MRAM designs, our initial ferromagnetic Josephson junction designs rely on an applied field to set the state of the junction1–3. In a modern MRAM cell, the state is set by making use of spin-transfer torque or spin-orbit torques to electrical change the magnetic state. To date, there has not been the equivalent step taken with the superconducting junction counterparts. This project will suit a student with a strong background in condensed matter physics or materials physics and excellent experimental skills. A successful student will gain experience in thin film deposition techniques, micro and nanoscale device fabrication, low temperature measurements in addition to a deep knowledge of the rapidly growing field of superconducting spintronics. 1. Satchell, N. et al. Spin-valve Josephson junctions with perpendicular magnetic anisotropy for cryogenic memory. Appl. Phys. Lett. 116, 022601 (2020). 2. Bell, C., Burnell, G., Leung, C.-W., Tarte, E. J. & Blamire, M. G. Spin Valve Josephson Junctions. IEEE Trans. Appiled Supercond. 15, 908–911 (2005). 3. Baek, B., Rippard, W. H., Benz, S. P., Russek, S. E. & Dresselhaus, P. D. Hybrid superconducting-magnetic memory device using competing order parameters. Nat. Commun. 5, 3888 (2014).

<h2 class="heading">How to apply</h2>

Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the Planned Course of Study that are applying for PHD Physics & Astronomy FT, in the research information section that the research degree you wish to be considered for is Electrically Switchable Ferromagnetic Josephson Junctions as well as <a href="https://condensed-matter.leeds.ac.uk/people/gb/">Dr Gavin Burnell </a> as your proposed supervisor and in the finance section, please state clearly the funding that you are applying for, if you are self-funding or externally sponsored. If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below). As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability. Applications will be considered on an ongoing basis. Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed. Please note that you must provide the following documents in support of your application by the closing date of Monday 6 January 2025 if applying for the China Scholarship Council-University of Leeds Scholarship, Monday 3 February 2025 if applying for Leeds Doctoral Scholarship or Tuesday 1 April 2025 for Leeds Opportunity Research Scholarship. If you are applying with external sponsorship or you are funding your own study, please ensure you provide your supporting documents at the point you submit your application: <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> </ul>

<h2 class="heading heading--sm">Entry requirements</h2>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

<h2 class="heading heading--sm">English language requirements</h2>

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<h2 class="heading">Funding on offer</h2>

Self-Funded or externally sponsored students are welcome to apply. UK – The<a href="https://phd.leeds.ac.uk/funding/138-leeds-doctoral-scholarship-2025-faculty-of-engineering-and-physical-sciences#:~:text=Key%20facts&text=One%20Leeds%20Doctoral%20Scholarship%20is,rata%20for%20part%2Dtime%20study."> Leeds Doctoral Scholarship</a> (closing date: Monday 3 February 2025) and <a href="https://phd.leeds.ac.uk/funding/234-leeds-opportunity-research-scholarship-2022">Leeds Opportunity Research Scholarship</a> (closing date: Tuesday 1 April 2025) are available to UK applicants. <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds. Non-UK – The <a href="https://phd.leeds.ac.uk/funding/48-china-scholarship-council-university-of-leeds-scholarships-2021">China Scholarship Council - University of Leeds Scholarship</a> is available to nationals of China (closing date: Monday 6 January 2025). The <a href="https://phd.leeds.ac.uk/funding/73-leeds-marshall-scholarship">Leeds Marshall Scholarship</a> is available to support US citizens. <a href="https://phd.leeds.ac.uk/funding/60-alumni-bursary">Alumni Bursary</a> is available to graduates of the University of Leeds. You will be responsible for paying the overtime fee in full in your writing up/overtime year (£320 in Session 2024/25), but the scholarship maintenance allowance will continue to be paid for up to 6 months in the final year of award. Important: Please note that that the award does not cover the costs associated with moving to the UK. All such costs (<a href="https://www.leeds.ac.uk/international-visas-immigration/doc/applying-student-visa">visa, Immigration Health Surcharge</a>, flights etc) would have to be met by yourself, or you will need to find an alternative funding source. Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.

<h2 class="heading">Contact details</h2>

For further information about your application, please contact PGR Admissions by email to <a href="mailto:maps.pgr.admissions@leeds.ac.uk">maps.pgr.admissions@leeds.ac.uk</a> For further information about this project, please contact Dr Gavin Burnell by email to <a href="mailto:G.Burnell@leeds.ac.uk">G.Burnell@leeds.ac.uk</a>

<h3 class="heading heading--sm">Linked research areas</h3>