The conductance of edge states of two-dimensional topological insulators

Date: 24 November 2017

Venue: UAntwerpen, Campus Groenenborger, Room U.247 - Groenenborgerlaan 171 - 2020 Antwerpen

Time: 10:00 AM - 11:00 AM

Short description: Condensed Matter Theory seminar presented by Prof Thomas Schmidt from the University of Luxemburg

Two-dimensional topological insulators are characterized by behaving as insulators in the bulk whilst hosting metallic edge states. In the presence of time-reversal symmetry, these edge states have been predicted to be robust against certain backscattering mechanisms, which might make them promising candidates for low-dissipation electronics devices.

Experiments in various materials have indeed found evidence for these edge states, recently even at non-cryogenic temperatures, but dissipation always seems to be significant.  Hence, it remains a question whether ideal edge states, i.e., in samples free of disorder, might at least theoretically allow for dissipationless transport.

In this talk, I will present the most important backscattering mechanisms which are effective in topological insulator edge states. Interactions either among electrons or between electrons and phonons are required to produce dissipation. I will discuss the importance of the possible interaction processes in different temperature ranges and for different system lengths, and thus estimate the maximal conductivity of an ideal edge state.

Contact email: