Physics PhD studentship (aligned to EPSRC CDT in Metamaterials): Optical detection of magnetization dynamics induced by spin-orbit torques Ref: 3031

About the award

The studentship is aligned to the UK’s Centre of Doctoral Training in Metamaterials (XM2) based in the Departments of Physics and Engineering on the Streatham Campus in Exeter.  Its aim is to undertake world-leading research, while training scientists and engineers with the relevant research skills and knowledge, and professional attributes for industry and academia.

Please see our website for more details about the centre and programme www.exeter.ac.uk/metamaterials.

Joint supervisors: Prof R J Hicken; Dr P S Keatley

Statement of Research

The injection of electrical current into multilayered magnetic materials can generate spin-orbit torques (SOTs) capable of modifying the magnetic state. The use of SOTs provides new opportunities for writing data in magnetic random access memory (MRAM), exciting precession in spin transfer oscillators (STOs), and driving magnetic objects such as domain walls, vortices and skyrmions.  However, the contribution made by different underlying microscopic mechanisms, such as the spin Hall and Rashba effects, to the observed SOTs remains controversial.  This is because firstly, SOTs are sensitive to atomic scale structural features, and secondly, conventional electrical measurement techniques offer limited access to the detailed magnetic state.

The PhD studentship is available in conjunction with a new EPSRC funded project (EP/P008550/1) in which time resolved scanning Kerr microscopy (TRSKM) will be used to quantify SOTs in planar devices for which the physical structure, particularly at the interfaces, has been carefully characterized. This internationally unique optical measurement technique will allow the magnetization to be probed directly for the first time, without reliance on electrical measurements, and with nanoscale spatial resolution.  The SOTs will be quantified through measurements of both the static orientation of the vector magnetization, and its precession.  Using the same TRSKM, time resolved measurements will be made of SOT induced switching when a pulsed current is applied, and of the steady state precession that may be induced by a constant current.  Crucially, the measurements will determine the spatial character of these processes, revealing the interplay between SOTs and the resonant mode spectrum of a specific sample or device geometry.  We will hence gain insight into how SOTs may be manipulated and best exploited in device operation.

You will be part of an international collaboration in which samples and devices of the highest quality are obtained from HGST in San Jose California, Brown University in Rhode Island, and the University of Gothenburg.  There is potential for travel to the partner sites to build understanding of sample fabrication and for discussion of results.  You will also be expected to present the results of your research at international conferences. 

Funding is available for a summer student project of up to 3 months prior to the start of the PhD.

International students are welcome to apply: project costs and the stipend will be paid, but applicants will need to provide evidence of how they will pay the international component of the fees.

Contact for informal enquiries: For more information about the project and informal enquiries, please contact the primary supervisor, Prof R J Hicken.

 

Summary

Application deadline:30th April 2018
Number of awards:1
Value:For eligible students the studentship will cover UK/EU tuition fees plus an annual tax-free stipend of at least £14,553 for 39 months full-time, or pro rata for part-time study. A paid 3 months summer student project prior PhD start is available.
Duration of award:per year
Contact: Prof. Alastair Hibbins (Admissions Tutor)metamaterials@exeter.ac.uk

How to apply

Application criteria

During the application process you will need to upload the documents listed below. Please prepare these before starting the application process.

  • A statement describing why you would like to study for a PhD in Physics,
  • A statement describing why you are considering a PhD programme that offers a cohort-based doctoral training model,
  • An academic CV,
  • A document outlining your research interests and any relevant expertise,
  • Degree transcript(s) giving information about the qualification awarded, the modules taken during the study period, and the marks for each module taken.

You will be asked to provide the contact details of two academic referees.

Application procedure

Applications should be made via the Apply Online system.  Please email metamaterials@exeter.ac.uk if you have any queries about this process. 

You will need to specify that you are making a Research application, with a keyword search of Metamaterials, specifying the College of Engineering, Mathematics and Physical Sciences, and Full Time.  Please then select the course, Physics / Engineering (CDT) - Metamaterials - Doctor of Philosophy - (Full Time) with the start date September 2017.

Shortlisting and interviews

Applications will be reviewed by members of the XM2 management board and candidates will be short-listed against a set of agreed criteria to ensure quality while maintaining diversity. Failure to include all the the elements above may result in rejection. Criteria will include:

ESSENTIAL

  • Excellence in a lower degree in a relevant discipline;
  • Excellence in written and oral skills in English;
  • Evidence of knowledge of XM2 ethos, research themes and/or supervisors.

DESIRABLE

  • Specialist knowledge about one or more XM2 topics;
  • Research outputs (e.g. papers) and/or has undertaken training in research methodology (e.g. undergraduate research projects);
  • Ability to work collaboratively

Short-listed candidates will be interviewed by a panel of two academic members of staff drawn from the management board. If successful, a second interview will be undertaken by the potential academic supervisors for the student concerned. Offers are normally made shortly after a successful second interview.