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

Roni Ilan (1) , Jérôme Cayssol (1, 2, 3) , Jens H. Bardarson (1, 4) , Joel E. Moore (1, 4)

1 Department of Physics [Berkeley]
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine
3 MPI-PKS - Max-Planck-Institut für Physik komplexer Systeme
4 Materials Science Division [LBNL Berkeley]

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

Keywords: Spin polarized transport; Integrable systems; Fermions in reduced dimensions; Electronic transport in nanoscale materials and structures

Domains: Condensed Matter [cond-mat]

Roni Ilan, Jérôme Cayssol, Jens H. Bardarson, Joel E. Moore. Non-Equilibrium Transport Through a Gate-Controlled Barrier on the Quantum Spin Hall Edge. Physical Review Letters, 2012, 109 (21), pp.216602. ⟨10.1103/PhysRevLett.109.216602⟩. ⟨hal-00755358⟩