Growth and Characterisation of Topological Insulator Nanostructures with Scanning Tunneling Microscopy.
Dr Tobias Maerkl
Postdoctoral Fellow, Nanotechnology Group, Physics & Astronomy, University of Canterbury
Time & Place
Fri, 21 Jul 2017 11:00:00 NZST in Rutherford Building, Level 5, Room 531
All are welcome
Theoretical works about topological materials date back to the discovery of the Quantum Hall Effect. But it has only been ten years since the first topological insulators were confirmed experimentally. Since then, the field of topological materials has become one of the hottest topics in condensed matter physics. It promises highly energy-efficient electronics through near lossless conduction in surface or edge states, potential for quantum computing, and exciting ways to study fundamental physics, such as Majorana Fermions.
As new electronic devices must inevitably be made of nanoscale components, one can naturally ask how to fabricate nanostructures with the desired properties. Moreover, it is still an unanswered question to what extent the topological properties of a material survive a reduction in size and dimensionality.
One recent trend has been to search for topological properties among the two-dimensional materials. Stacking these in so-called van-der-Waals heterostructures opens up another route to combining and creating different functionalities. As one of the key ingredients for topological effects is a strong spin-orbit coupling, our search focuses on 2d materials made of some of the heavy elements. In our experiments we grow essentially two-dimensional bismuthene and antimonene nanoislands and use scanning tunneling microscopy to characterise the structures. I will give a short introduction to the field of topological materials and then present an overview of our current activities, recent findings, challenges and chances.
Background.. Tobias gained his Diploma in Physics (2011) and PhD (2015) in Germany at the Karlsruhe Institute of Technology (KIT, formerly University of Karlsruhe). For both degrees he worked on topics in experimental solid state physics in the research group of Prof W. Wulfhekel, using low-temperature scanning tunneling microscopy (STM).