Voltage controlled spin injection in a (Ga,Mn)As/(Al,Ga)As Zener diode

TL;DR

This paper presents a theoretical study of spin polarization in a (Ga,Mn)As/(Al,Ga)As Zener diode embedded in a light-emitting diode, using self-consistent simulations and tight-binding models to explain experimental observations.

Contribution

It introduces a combined self-consistent simulation and tight-binding approach to analyze spin injection and polarization in a complex heterostructure.

Findings

High magnitude of spin polarization observed experimentally.

Strong bias dependence of the spin polarization.

Theoretical model successfully explains experimental results.

Abstract

The spin polarization of the electron current in a p-(Ga,Mn)As-n-(Al,Ga)As-Zener tunnel diode, which is embedded in a light-emitting diode, has been studied theoretically. A series of self-consistent simulations determines the charge distribution, the band bending, and the current-voltage characteristics for the entire structure. An empirical tight-binding model, together with the Landauer- Buttiker theory of coherent transport has been developed to study the current spin polarization. This dual approach allows to explain the experimentally observed high magnitude and strong bias dependence of the current spin polarization.