Multi-channel scattering mechanism behind the re-entrant conductance feature in nanowires subject to strong spin-orbit coupling

Abstract

The characterization of helical states can be performed by checking the existence of the re-entrant behaviour, which appears as a dip in the conductance probed in nanowires (NWs) with strong spin-orbit coupling (SOC) and under perpendicular magnetic field. On the other hand, the experiment described in Ref. 1 observed the re-entrant behaviour in the absence of a magnetic field, which was explained through spin-flipping two-particle backscattering. We theoretically show that the observation of the re-entrant behaviour is due to a multi-channel scattering mechanism, which causes a reduction of the transmission when an effective attractive potential and coupling between different channels are present. Both ingredients are provided by the SOC in the transport properties of NWs.