Active Control of Topological Devices for Quantum Integration

Topological Insulators (TIs) are materials that possess a topological surface state (TSS). This surface state allows for low-loss electrical transport, integration of spin/electrical/optical signals and the formation of bound Majorana states for topological quantum computation. [1,2] We have recently developed the ability to grow highly crystalline heterostructures of TIs and organic dyes that produce an interface with tuneable topological behaviour. This project will develop growth, lithography and processing techniques to facilitate the integration of these topological quantum technologies with conventional semiconductors by creating active devices in which the surface can be precisely tuned to turn topological effects on and off with a gate bias.

<p>Methods to engineer the TSS have been developed utilising implanted dopants, but these cannot be actively controlled, and therefore cannot be used to make topological logic devices. [3] We have recently developed the ability to grow highly crystalline heterostructures of TIs and organic dyes, and shown that they produce an interface with tuneable topological behaviour. We are now encapsulating these structures with graphene to create gate contacts, developing multi-organic layers to precisely tune surface properties and creating ultra-thin TI layers to exploit quantum confinement effects.</p> <p>This project will develop growth, lithography and processing techniques to create active devices based on these heterostructures in which the surface can be precisely tuned to turn topological effects on and off with a gate bias. This will facilitate the integration of quantum technologies with conventional semiconductors.</p> <p>These devices will be characterised by a combination of THz spectroscopy and Electron Energy Loss Spectroscopy (EELS), using the facilities of the Bragg Centre. This will include an exploration of how these devices can be used to couple spintronic and photonic outputs to semiconducting logic. As well as demonstrating a novel device, this will also develop useful techniques for integrating TIs into industrial semiconductor processes.</p> <p>The student will develop critical skills in semiconductor growth, lithography and microscopy, placing them in a&nbsp;competitive position to make expert contributions to UK semiconductor and quantum technology in their future career.</p> <p>This studentship will be part of an exciting new Doctoral Training Initiative called UK Semiconductor Industry Future Skills or UK-SIFS for short. UK-SIFS will create a vibrant, multi-disciplinary cohort experience for all our students and provide highly practical training of substantial value to those interested in careers in the semiconductor and related sectors such as photonics and clean energy manufacturing, research and development, innovation, and commercialisation of technology. The student will also have a chance to work with a large range of industrial partners who will not only deliver training content but also co-supervise research and host secondments. Possible locations who have offered visits are NPL, KLA, IQE, QinetiQ and Edwards.</p> <p>References:</p> <p>[1] &ndash; R Aguado, L P Kouwenhoven. Physics Today, 73, 6, 2020.</p> <p>[2] &ndash; M He et al, Frontiers of Physics, 14, 4, 2019.</p> <p>[3] &ndash; M Bianchi et al, ACS Nano, 6, 8, 2012.</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>Active Control of Topological Devices for Quantum Integration</em></strong>&nbsp;as well as <a href="https://eps.leeds.ac.uk/physics/staff/9991/timothy-moorsom">Dr Timothy Moorsom</a>&nbsp;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 Timothy Moorsom by email to&nbsp;<a href="mailto:T.Moorsom@leeds.ac.uk">T.Moorsom@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>