Non-collinear Spin Valve Effect in Ferromagnetic Semiconductor Trilayers

TL;DR

This paper reports the observation of a non-collinear spin valve effect in ferromagnetic semiconductor trilayers, showing positive magnetoresistance peaks due to spin-dependent scattering at interfaces.

Contribution

It demonstrates the existence of a non-collinear spin valve effect in (Ga,Mn)As trilayers, highlighting the role of interface scattering and annealing conditions.

Findings

Positive magnetoresistance peaks observed in orthogonal magnetization configurations

Effect depends on spacer layer thickness and annealing conditions

Spin-dependent scattering at interfaces is the primary mechanism

Abstract

We report the observation of the spin valve effect in (Ga,Mn)As/p-GaAs/(Ga,Mn)As trilayer devices. Magnetoresistance measurements carried out in the current in plane geometry reveal positive magnetoresistance peaks when the two ferromagnetic layers are magnetized orthogonal to each other. Measurements carried out for different post-growth annealing conditions and spacer layer thickness suggest that the positive magnetoresistance peaks originate in a noncollinear spin valve effect due to spin-dependent scattering that is believed to occur primarily at interfaces.