Topological quantum structures in bismuth ferrite superlattices

Topologically non-trivial structures with particle-like properties in condensed matter systems, known as skyrmions, have recently been proposed for quantum computing. Though skyrmions have been observed in both ferromagnetic and ferroelectric materials with sizes in the nanometre range, identifying optimal materials to control these quantum objects remains difficult. This project will create multiferroic bismuth ferrite (BFO) superlattices in which there are alternating layers of BFO and another oxide to generate topological quantum structures as a result of strain at the interfaces. The project will further explore the control of these quantum structures through the application of electric fields as a pre-requisite for manipulating quantum information.

<p>Topologically non-trivial structures with particle-like properties in condensed matter systems,known as skyrmions, have recently been proposed for quantum computing. One of the keychallenges for quantum computing with skyrmions is identifying optimal materials, and crucially, to be considered a quantum object the size of the skyrmion must be on the order of nanometres.</p> <p>Skyrmions have been observed in both ferromagnetic and ferroelectric materials, and in one&nbsp;instance topological structures as small as 3 nm have been revealed.</p> <p>In this project we propose to deposit multiferroic bismuth ferrite (BFO) superlattices in which&nbsp;there are alternating layers of BFO and another oxide such as strontium titanate (STO) or&nbsp;strontium ruthenate (SRO). As a multiferroic, BFO offers exciting prospects over and above purely&nbsp;ferromagnetic or ferroelectric materials, as the coexistence of both polar and spin topologies&nbsp;would enable e.g. electric field control of the magnetism. At the interfaces of the BFO layers in a&nbsp;superlattice, strain and depolarisation effects can combine to curl the polarisation and generate&nbsp;topological quantum structures.</p> <p>The superlattices will be grown in the Royce deposition facility and characterised by electron&nbsp;microscopy, X-ray diffraction and scanning probe microscopy using the Bragg Centre facilities. We&nbsp;will establish the growth conditions for observation of topological structures. Further, by applying&nbsp;an electric field, we aim to tune the topology of the structures as a pre-requisite for manipulating&nbsp;quantum information. Finally, we will investigate the potential for macroscopic quantum&nbsp;tunnelling between the structures.</p>

<p>Formal applications for research degree study should be made online through the&nbsp;<a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University&#39;s website</a>. Please state clearly in the Planned Course for Study section that you are applying for&nbsp;<em><strong>EPSRC DTP Engineering &amp; Physical Sciences</strong></em>, in the research information section&nbsp;that the research degree you wish to be considered for is&nbsp;<strong><em>Topological quantum structures in bismuth ferrite superlattices</em></strong>&nbsp;as well as <a href="https://eps.leeds.ac.uk/physics/staff/4118/dr-thomas-moore">Dr Thomas Moore</a> as your proposed supervisor and&nbsp;<em><strong>in the Finance section, please state that the funding source you are applying for is EPSRC Quantum Technologies&nbsp;Doctoral Training Studentship</strong></em>.</p> <p>If English is not your first language, you must provide evidence that you meet the University&#39;s minimum English language requirements (below).</p> <p><em>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.</em></p> <p>Applications will be considered on an ongoing basis. &nbsp;Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. &nbsp;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.</p> <p>Please note that you must provide the following documents at the point you submit your application:</p> <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>

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.

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.

<p>A highly competitive EPSRC Quantum Technologies Doctoral Training Partnership Studentship offering the award of fees, together with a tax-free maintenance grant of &pound;19,237 per year for 3.5 years.&nbsp; Training and support will also be provided.<br /> <br /> This opportunity is open to UK applicants only.<br /> <br /> Please refer to the&nbsp;<a href="https://www.ukcisa.org.uk/">UKCISA</a>&nbsp;website for&nbsp;information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information regarding your application, please contact Doctoral College Admissions by email to&nbsp;<a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a></p> <p>For further information regarding this project, please contact Dr Thomas Moore&nbsp;by email to <a href="mailto:T.A.Moore@leeds.ac.uk">T.A.Moore@leeds.ac.uk</a>.</p> <p>For information about Quantum Technologies or the Bragg Centre for Materials Research, please email&nbsp;<a href="mailto:BraggCentre@leeds.ac.uk">BraggCentre@leeds.ac.uk</a>.</p>