Abstract

Topological insulators (TIs) and their protected spin-momentum locked surface states (TSSs) have generated a great deal of interest within the field in the last few years. Since the discovery of Bi2Se3 as a TI with a Dirac cone at the surface, many questions have arisen about further understanding the properties of these states.

This project asks two questions: how do surface states tunnel and how can they be patterned?

We aim to use momentum-resolved tunnelling spectroscopy to map out the dispersion relation of the TSS , and to measure whether spin is preserved during the tunnelling process. We also investigate ways to pattern the TSS : this is protected with time-reversal symmetry, so using the magnetic proximity effect to break the TSS in selected regions seems to be a promising approach.

I will outline the theory and principles behind these questions and the research plan we have devised to tackle this and present our preliminary results.