Nonequilibrium Transport Through a Gate-Controlled Barrier on the Quantum Spin Hall Edge

ORAL

Abstract

The quantum spin Hall insulator is characterized by the presence of gapless helical edge states where the spin of the charge carriers is locked to their direction of motion. In order to probe the properties of the edge modes, we propose a design of a tunable quantum impurity realized by a local gate under an external magnetic field. Using the integrability of the impurity model, the conductance is computed for arbitrary interactions, temperatures and voltages, including the effect of Fermi liquid leads. The result can be used to infer the strength of interactions from transport experiments.

*The authors acknowledge support from AFOSR MURI (RI), the ONR EU/FP7 under contract TEMSSOC and from ANR through project 2010- BLANC-041902 (ISOTOP) (JC), the Nanostructured Thermoelectrics program of LBNL (JHB), and DARPA (JEM).

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Authors

  • Roni Ilan

    • UC Berkeley
    • University of California, Berkeley

  • Jerome Cayssol

    • Max-Planck-Institut f\"ur Physik Komplexer Systeme, Dresden, Germany and LOMA (UMR-5798), CNRS and University Bordeaux, Talence, France

  • Jens Bardarson

    • University of California, Berkeley and the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA

  • Joel Moore

    • University of California, Berkeley and the Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA