Quasi-reversible Magnetoresistance in Exchange Spring Tunnel Junctions

TL;DR

This paper demonstrates a large, quasi-reversible tunnel magnetoresistance effect in exchange-biased ferromagnetic semiconductor tunnel junctions, driven by an exchange spring in the ext{GaMnAs} layer, highlighting a new magnetic tunneling phenomenon.

Contribution

It introduces the observation of quasi-reversible magnetoresistance in exchange-biased semiconductor tunnel junctions due to exchange spring formation.

Findings

Large, quasi-reversible tunnel magnetoresistance observed

Magnetoresistance highly sensitive to exchange spring state

Inhomogeneous magnetization region influences tunneling behavior

Abstract

We report a large, quasi-reversible tunnel magnetoresistance in exchange-biased ferromagnetic semiconductor tunnel junctions wherein a soft ferromagnetic semiconductor (\gma) is exchange coupled to a hard ferromagnetic metal (MnAs). Our observations are consistent with the formation of a region of inhomogeneous magnetization (an "exchange spring") within the biased \gma layer. The distinctive tunneling anisotropic magnetoresistance of \gma produces a pronounced sensitivity of the magnetoresistance to the state of the exchange spring.