Anomalous Rashba spin-orbit interaction in InAs/GaSb quantum wells

TL;DR

This paper theoretically studies the Rashba spin-orbit interaction in InAs/GaSb quantum wells, revealing its dependence on layer thickness, nonlinear and oscillating behaviors, and asymmetry with electric field direction.

Contribution

It uncovers the detailed dependence of Rashba spin-splitting on quantum well thickness and electric field, highlighting nonlinear and oscillating behaviors.

Findings

Rashba spin-splitting depends on InAs layer thickness

Nonlinear behavior in narrow quantum wells

Oscillating Rashba spin-splitting in wide quantum wells

Abstract

We investigate theoretically the Rashba spin-orbit interaction in InAs/GaSb quantum wells(QWs). We find that the Rashba spin-splitting (RSS) depends sensitively on the thickness of the InAs layer. The RSS exhibits nonlinear behavior for narrow InAs/GaSb QWs and the oscillating feature for wide InAs/GaSb QWs. The nonlinear and oscillating behaviors arise from the weakened and enhanced interband coupling. The RSS also show asymmetric features respect to the direction of the external electric field.