Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 13: Transport: Topological Insulators - 2D
(Joint session of DS, HL, MA, O and TT organized by TT)

TT 13.1: Vortrag

Montag, 7. März 2016, 15:00–15:15, H18

Probing the spin texture of generic helical edge states with an antidot — •Alexia Rod^1,2, Giacomo Dolcetto¹, Thomas L. Schmidt¹, and Stephan Rachel² — ¹Physics and Materials Science Research Unit, University of Luxembourg, Luxembourg — ²Institut für Theoretische Physik, TU Dresden, Germany

Edge states of time-reversal topological insulators are generally described as helical edge states, where the spin-axis symmetry is conserved. However, this symmetry is usually not guaranteed in experimental realizations. In its absence, the most general model to describe edge states is called generic helical liquid. Using this framework, a rotation of the spin quantization axis has been predicted, independently of the microscopic model and of the considered geometry [1, 2].

Here we propose a scheme to probe the spin texture of the edge states on a transport device. We investigate the transport properties of generic helical edge states in a two-dimensional topological insulator bar with an antidot in its center. We show that the conductance is implicitly dependent of the spin texture in the case of uniform bulk or structural inversion asymmetry. We also study sequential tunneling and cotunneling in presence of Coulomb interaction due to electron confinement on the antidot.
T.L. Schmidt, S. Rachel, F. von Oppen, L. Glazman,

PRL 108, 156402 (2012).
A. Rod, T.L. Schmidt, S. Rachel, PRB 91, 245112 (2015).