Dresden 2017 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 76: Poster Session: Transport 2

TT 76.19: Poster

Donnerstag, 23. März 2017, 15:00–19:00, P2-OG1

Planar Hall effect and anisotropic magnetoresistance from the surface states of disordered 3D topological insulators — •Henry Legg and Achim Rosch — Institute for Theoretical Physics, University of Cologne, Zülpicher Straße 77, D-50937, Köln, Deutschland

In the presence of time-reversal symmetry electrons on the surface of a topological insulator cannot backscatter from disorder. A magnetic field parallel to the surface lifts this protection mechanism, enabling backscattering which is predominantly in the direction parallel to the magnetic field but retaining the Dirac physics of the surface. As a result the anisotropy of magnetoresistance parallel and perpendicular to B is a sensitive probe of the loss of topological protection when time-reversal symmetry is broken.

Using a self-consistent T-matrix approximation, including vertex corrections, we demonstrate how an in-plane magnetic field can dramatically alter the resistivity of a topological insulator’s surface. We compare our theoretical results to experiments where the dependence on gate voltage provides an especially clear experimental signature of the scattering mechanism.