Ahmet Suna: PhD at Queen’s University Belfast, UK


Moveable Domain Wall Electronics in Single Crystal Ferroelectric Sheets


Professor Marty Gregg

Non-academic Supervisor:

Dr. Bernd Gotsmann (IBM Research Zurich, Switzerland)

Domain Walls in Memristive and Active Junction Devices

This project will seek to build on two of our recent discoveries: firstly, that conducting domain wall arrays in single crystal ion-sliced LiNbO3can act as excellent memristors, with accessible state densities comparable to those seen in ferroelectric tunnel junctions and unexplained synaptic “plasticity”; secondly, that both p-n and tunnel barrier junctions can exist inside domain walls themselves (in several improper ferroelectric systems), creating “in-domain wall” devices. Fully mapping and understanding the nature of both of these aspects of domain wall functionality will be the main thrusts of the research. The main part of the research will be performed at Queen’s University in Belfast. Additionally, the ESR will spend the secondments at Ecole Polytechnique Federal de Lausanne, Switzerland for detailed domain wall characterization under SPM (1 Month) and at IBM Research – Zurich, Switzerland for the development of nanocircuitry (1 Month).

Queen’s University Belfast (QUB) was chartered in 1845 and opened in 1849 as “Queen’s College Belfast”. It is a vibrant university, which is strong in both teaching and research and sits comfortably within the top 200 in the world (QS World University Rankings). The main campus is situated beautifully, near to the city’s Botanical Gardens, Ulster Museum, Queen’s Film and Lyric Theatres. The university has a rich academic heritage in physics, with Paul Ewald (the Ewald Sphere) as an ex-member of staff and both Joseph Larmor (Larmor precession) and John Bell (Bell’s inequalities) as former students.

The environment for advanced functional materials research in QUB is enviable: researchers have ready access to excellent equipment and processing facilities, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), focused ion beam (FIB), atomic force microscopy (AFM), a superconducting quantum interference device (SQUID), interferometry, surface profilometry, pulsed laser deposition (PLD), magneto-optic Kerr effect microscopy (MOKE), sputtering, photolithography and Argon ion milling to name a few!

Additional information for applicants

  • We look for a candidate with a master/bachelor degree in Physics, Materials Science and/or Chemistry, or combination thereof.
  • Local application requirements apply:
    • English Language Requirements. Please visit the QUB website for more information.
    • The normal minimum requirement for admission to a research degree programme is an Upper Second Class Honours Degree from a UK or ROI Higher Education Provider or an equivalent qualification acceptable to the University. Please visit the QUB website for more information.


For more details on the project, contact