Robustness of spin filtering against current leakage in a Rashba-Dresselhaus-Aharonov-Bohm interferometer

TL;DR

This paper demonstrates that a previously proposed spin filter maintains full spin polarization even with electron leakage, and its polarization can be controlled via electric and magnetic fields by tuning the interferometer's symmetry.

Contribution

It shows the robustness of spin filtering against current leakage and how to control polarization through external fields in a Rashba-Dresselhaus-Aharonov-Bohm interferometer.

Findings

Full spin polarization remains despite electron leakage.

Polarization can be tuned by electric and magnetic fields.

Symmetry tuning enables control of spin filtering.

Abstract

In an earlier paper [Phys. Rev. B 84, 035323 (2011)], we proposed a spin filter which was based on a diamond-like interferometer, subject to both an Aharonov-Bohm flux and (Rashba and Dresselhaus) spin-orbit interactions. Here we show that the full polarization of the outgoing electron spins remains the same even when one allows leakage of electrons from the branches of the interferometer. Once the gate voltage on one of the branches is tuned to achieve an effective symmetry between them, this polarization can be controlled by the electric and/or magnetic fields which determine the spin-orbit interaction strength and the Aharonov-Bohm flux.