Current and strain-induced spin polarization in InGaN/GaN superlattices

TL;DR

This paper reports on the observation and control of current-induced spin polarization in InGaN/GaN superlattices, highlighting the influence of strain and the potential for spin current generation without magnetic fields.

Contribution

It demonstrates strain-tunable spin Hall effect in InGaN/GaN superlattices and provides a theoretical understanding of strain-induced spin polarization.

Findings

Spin polarization sign reverses with current direction.

Spin Hall effect is controllable via internal strain.

Theoretical model explains strain-induced spin polarization.

Abstract

The lateral current-induced spin polarization in InGaN/GaN superlattices (SLs) without an applied magnetic field is reported. The fact that the sign of the nonequilibrium spin changes as the current reverses and is opposite for the two edges provides a clear signature for the spin Hall effect. In addition, it is discovered that the spin Hall effect can be strongly manipulated by the internal strains. A theoretical work has also been developed to understand the observed strain induced spin polarization. Our result paves an alternative way for the generation of spin polarized current.