Magnetoconductance correction in zinc-blende semiconductor nanowires with spin-orbit coupling

TL;DR

This paper investigates how spin-orbit coupling influences magnetoconductance in zinc-blende semiconductor nanowires, highlighting the effects of Dresselhaus and Rashba interactions on spin relaxation and fitting the model to experimental data.

Contribution

It introduces a comprehensive model for spin-orbit effects in nanowires without surface accumulation layers, including the impact of wire radius on Rashba spin relaxation.

Findings

Dresselhaus spin relaxation rate is independent of spin component and wire direction.

Rashba spin relaxation rate decreases with smaller wire radius.

Model fits experimental magnetoconductance data and extracts transport parameters.

Abstract

We study the effects of spin-orbit coupling on the magnetoconductivity in diffusive cylindrical semiconductor nanowires. Following up on our former study on tubular semiconductor nanowires, we focus in this paper on nanowire systems where no surface accumulation layer is formed but instead the electron wave function extends over the entire cross section. We take into account the Dresselhaus spin-orbit coupling resulting from a zinc-blende lattice and the Rashba spin-orbit coupling, which is controlled by a lateral gate electrode. The spin relaxation rate due to Dresselhaus spin-orbit coupling is found to depend neither on the spin density component nor on the wire growth direction and is unaffected by the radial boundary. In contrast, the Rashba spin relaxation rate is strongly reduced for a wire radius that is smaller than the spin precession length. The derived model is fitted to the data of magnetoconductance measurements of a heavily doped back-gated InAs nanowire and transport parameters are extracted. At last, we compare our results to previous theoretical and experimental studies and discuss the occurring discrepancies.