Spin rotation, spin filtering, and spin transfer in directional tunneling through non-centrosymmetric semiconductor barriers

TL;DR

This paper investigates how spin-orbit interaction and lack of inversion symmetry in gallium arsenide barriers influence spin-dependent tunneling, revealing spin filtering effects that could advance spintronic device control.

Contribution

It provides a detailed analysis of spin-dependent tunneling in non-centrosymmetric semiconductors, highlighting the role of spin splitting and orientation-dependent effects.

Findings

Spin splitting causes spin filtering during tunneling.

Evanescent states are spin split due to lack of inversion symmetry.

Crystallographic direction affects spin filtering efficiency.

Abstract

We consider spin-dependent tunneling through a gallium arsenide barrier, a material which has no inversion symmetry. We are dealing with free electrons, with one effective mass and a spin-splitting in the barrier material. When we take into account both the spin-orbit interaction and the absence of the inversion symmetry, the evanescent states in the barrier are spin split and the tunneling process can become rather involved. Along some crystallographic directions, the incident wave experiences spin filtering during the tunneling. These results open stimulating perspectives for spin manipulation in tunnel devices.