Spin polarization control through resonant states in an Fe/GaAs Schottky barrier

TL;DR

This paper investigates how resonant interface states in Fe/GaAs Schottky barriers influence spin polarization, showing that it can be controlled by barrier properties and bias voltage, aligning well with experimental data.

Contribution

It reveals the role of band matching of resonant states in determining spin polarization sign and demonstrates control via bias voltage in Fe/GaAs junctions.

Findings

Spin polarization depends on Schottky barrier height.

Resonant interface states determine the sign of spin polarization.

Bias voltage can switch the polarization sign.

Abstract

Spin polarization of the tunnel conductivity has been studied for Fe/GaAs junctions with Schottky barriers. It is shown that band matching of resonant interface states within the Schottky barrier defines the sign of spin polarization of electrons transported through the barrier. The results account very well for experimental results including the tunneling of photo-excited electrons, and suggest that the spin polarization (from -100% to 100%) is dependent on the Schottky barrier height. They also suggest that the sign of the spin polarization can be controlled with a bias voltage.