Berlin 2015 – scientific programme
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PV: Plenarvorträge
PV X
PV X: Prize Talk
Tuesday, March 17, 2015, 14:00–14:30, H 0104
Classification of topological quantum matter with symmetries — •Andreas Schnyder — Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany — Laureate of the Walter-Schottky-Prize
Topological materials have in recent years become a subject of intense research due to fundamental considerations as well as potential use for technical applications in device fabrication and quantum information. One of the hallmarks of topological materials is the existence of protected exotic zero-energy surface states, which arise as a consequence of a nontrivial topology of the bulk wave functions. In this talk, starting from the ten-fold classification of topological insulators and superconductors, I will survey recent developments, with a particular emphasis on the topological classifications of fully gapped and gapless materials in terms of crystal reflection symmetries. As concrete examples, I discuss the Dirac materials Ca3PbO and Sr3PbO and show that these antiperovskites are reflection-symmetry-protected topological insulators. The Dirac surface states of these materials are protected by a non-zero mirror Chern number, which can take on only even values. If time permits, I will also present some results about the topological properties of the Dirac material Na3Bi and of some noncentrosymmetric superconductors. In particular, I will explain how reflection symmetry gives rise to protected arc surface states in these topological materials. I will discuss experimental signatures of these topological surface states in charge and thermal transport measurements, as well as in Fourier-transform scanning tunneling spectra.