Influence of structural deformations on the reentrant conductance feature in semiconducting nanowires

TL;DR

This paper studies how structural deformations in semiconducting nanowires influence the reentrant conductance feature, revealing that local constrictions and expansions can significantly alter electronic transport properties.

Contribution

It introduces a numerical method to analyze the effects of deformations and mode coupling on conductance in nanowires, including cases without spin-orbit coupling or magnetic fields.

Findings

Conductance dips are affected by local constrictions.

Reentrant conductance features can occur without SOC or magnetic field.

The developed numerical approach includes multiple scattering channels.

Abstract

Helical states can be measured through the observation of the reentrant behaviour, which is a dip in the conductance probed in semiconducting nanowires (NWs) with strong spin-orbit coupling (SOC) under the presence of an external perpendicular magnetic field. We investigate the effects of deformations in the electronic transport in NWs considering the coupling between different transverse modes. Within this approach, we show that the dip in the conductance of a NW is affected by the presence of a local constriction. Moreover, we find that the reentrant feature in the conductance can appear in NWs with a local expansion of its radius, even in the absence of SOC and magnetic field. Furthermore, we develop a numerical approach to calculate transport properties, which is able to include the deformation and the coupling among several scattering channels.