Numerical simulations of a ballistic spin interferometer with the Rashba spin-orbital interaction

TL;DR

This paper numerically studies the conductance oscillations in a 1D square loop device with Rashba spin-orbit interaction, revealing dependence on spin precession and effects of disorder, aligning with recent experimental findings.

Contribution

It provides detailed numerical analysis of conductance oscillations in a 1D Rashba spin interferometer, highlighting the impact of spin-orbit strength and disorder on AAS and AB oscillations.

Findings

Both AAS and AB oscillations depend on spin precession angle.

Disorder suppresses AB oscillations but not AAS oscillations.

Node positions of AAS oscillations remain unchanged with disorder.

Abstract

We numerically investigate the transport behavior of a quasi one-dimension (1D) square loop device containing the Rashba spin-orbital interaction in the presence of a magnetic flux. The conductance versus the magnetic field shows the Al'tshuler-Aronov-Spivak (AAS) and Aharonov-Bohm (AB) oscillations. We focus on the oscillatory amplitudes, and find that both of them are strongly dependent on the spin precession angle (i.e. the strength of the spin-orbit interaction) and exhibit no-periodic oscillations, which are well in agreement with a recent experiment by Koga et al. [cond-mat/0504743(unpublished)]. However, our numerical results for the ideal 1D square loop device for the node positions of the amplitudes of the AB and AAS oscillations are found to be of some discrepancies comparing with quasi-1D square loop with a finite width. In the presence of disorder and taking the disorder ensemble average, the AB oscillation in the conductance will disappear, while the time-reversal symmetric AAS oscillation still remains. Furthermore, the node positions of the AAS oscillatory amplitude remains the same.