Spin current and electrical polarization in GaN double-barrier structures

TL;DR

This paper investigates how piezoelectric fields and electrical polarization in GaN double-barrier structures enhance tunnel spin injection efficiency and enable zero magnetic field spin control through strain engineering.

Contribution

It introduces a method to improve spin injection efficiency and control spin orientation in GaN structures by leveraging piezoelectric effects and electrical polarization.

Findings

Piezoelectric and spontaneous polarization increase spin injection efficiency.

Electrical polarization relates to spin orientation, enabling control.

Strain engineering allows zero magnetic field spin manipulation.

Abstract

Tunnel spin polarization in a piezoelectric AlGaN/GaN double barrier structure is calculated. It is shown that the piezoelectric field and the spontaneous electrical polarization increase an efficiency of the tunnel spin injection. The relation between the electrical polarization and the spin orientation allows engineering a zero magnetic field spin injection manipulating the lattice-mismatch strain with an Al-content in the barriers.