Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 53: Transport: Topological Insulators 3 (jointly with TT, MA)

HL 53.13: Vortrag

Mittwoch, 28. März 2012, 12:45–13:00, BH 334

Magnetoconductance of disordered HgTe strips — •Sven Essert and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany

Quantum wells of HgTe show the fascinating phenomenon of edge state transport which leads to a finite conductance in an energy window where the bulk material is insulating. This edge conductance exhibits special properties. One is, that it is expected to be stable against non-magnetic disorder because of a topological protection by time-inversion symmetry.

Inspired by this, we numerically investigate how the conductance of disordered HgTe strips of finite width changes under the application of a time-reversal symmetry breaking external magnetic field. We compare our results for different disorder models to experimental data.

Additionally, we study how the so-called "topological Anderson insulator" phase of HgTe strips, i.e. the phenomenon that finite disorder drives the metallic system into a quantum spin hall state with quantized edge conductance, is affected by the application of an external magnetic field.