Tight-binding model of spin-polarized tunnelling in (Ga,Mn)As-based structures

TL;DR

This paper presents a tight-binding model combined with the Landauer-Buettiker formalism to accurately describe high tunneling magnetoresistance and spin polarization in (Ga,Mn)As-based structures, aligning well with experimental data.

Contribution

It introduces a comprehensive theoretical approach to model spin-dependent tunneling in (Ga,Mn)As structures, accounting for carrier concentration and magnetic ion effects.

Findings

High TMR values in trilayers explained by the model

Significant spin polarization in Zener diodes matched by calculations

Carrier concentration and magnetic ions influence tunneling behavior

Abstract

The Landauer-Buettiker formalism combined with the tight-binding transfer matrix method is used to describe the results of recent experiments: the high tunneling magnetoresistance (TMR) in (Ga,Mn)As-based trilayers and highly polarized spin injection in p-(Ga,Mn)As/n-GaAs Zener diode. For both TMR and Zener spin current polarization, the calculated values agree well with those observed experimentally. The role played in the spin dependent tunneling by carrier concentration and magnetic ion content is also studied.