Topological insulator plasmonics

Topological insulators (TIs) are a new type of material that has recently been discovered. They have highly conductive surface states, while their bulk remains insulating. Because of extremely strong spin-orbit coupling in these materials, surface electrons have a spin-momentum locking texture, so that they are almost free from scattering, known as topological protection. The electrons are also massless Dirac particles similar to those in graphene, even at room temperature.<br /> <br /> While most work to-date has been focused on the use of TIs in electronic devices, there have recently been exciting theoretical proposals of how this new type of material interacts with light. These have predicted exotic light-matter interactions between the surface electrons in the TI and photons. Because the topologically protected carriers are confined to the surface of the material, by controlling the physical shape of the material on the nanometer scale the material interaction with light can be controlled. These interactions represent a new type of light-matter phenomena and could lead to applications in sensor technology, optical coatings and new laser technologies.

<p>The predicted interactions are strongest in the terahertz (THz) region of the spectrum that lies between the microware and infrared. It has traditionally been difficult to access this part of the spectrum, however, the UoL is a leader in this field and has a number of state-of-the-art THz laboratories. The THz region is ideal for this type of research because modern femtosecond lasers and nanofabrication technology are able to access timescales and length scales well below those of terahertz waves leading to very precise measurement and control of the electromagnetic field.</p> <p>This project will explore the interaction between THz light and TI nanostructured materials and will be based in the Bragg centre. The topological thin films will be grown using the recently commissioned Royce-funded multi-deposition chamber. The TI materials that will be studied are Bi₂Se₃, (Bi_1-xSb_x)₂Te₃ and TI-based heterostructures (e.g. TI p-n junction, TI/magnetic thin film or TI/supercondutor). Sample characterization will be carried out by a range of techniques available in the Bragg centre, including XRD, EDX, SEM and magnetoelectric transport measurements. The device fabrication will be carried out in the state-of-the-art nanofabrication facilities available in the nanotechnology cleanroom and measured in the THz laboratories.</p> <p>This project aims to identify exotic light-matter interactions such as the &ldquo;topological surface plasmon polariton&rdquo; that have been theoretically predicted. Demonstration of these new types of excitations and interactions will not only be of interest to scientific researchers, but open the way to a number of potential applications.</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 of Study section that you are applying for <em><strong>PHD Electronic &amp; Electrical Engineering FT</strong></em>&nbsp;in the research information section&nbsp;that the research degree you wish to be considered for is <em><strong>Topological insulator plasmonics</strong></em> as well as&nbsp;<a href="https://eps.leeds.ac.uk/electronic-engineering/staff/622/dr-joshua-freeman">Dr Joshua Freeman</a> as your proposed supervisor.</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 style="margin-bottom:11px"><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 class="MsoNoSpacing">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> <li>Funding information</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 class="MsoNoSpacing">A highly competitive EPSRC Doctoral Training Partnership Studentship consisting of the award of fees with a maintenance grant (currently &pound;17,668 for session 2022/23) for 3.5 years.</p> <p>This opportunity is open to UK applicants only.&nbsp; All candidates will be placed into the EPSRC Doctoral Training Partnership Studentship Competition and selection is based on academic merit.</p> <p>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 about this project, please contact Dr Joshua Freeman: <a href="mailto:j.r.freeman@leeds.ac.uk">j.r.freeman@leeds.ac.uk</a>&nbsp;or&nbsp;t: +44 (0)113 343 37128</p> <p>For further information about your application, please contact Doctoral College Admissions<br /> e:&nbsp;<a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a></p>