Magnetization dependent current rectification in (Ga,Mn)As magnetic tunnel junctions

TL;DR

This paper demonstrates that current rectification in (Ga,Mn)As magnetic tunnel junctions is strongly influenced by magnetization alignment, with the ability to switch rectification direction and amplitude using small spin-injection currents, linked to energy-dependent density of states.

Contribution

It reveals the magnetization-dependent control of current rectification in (Ga,Mn)As tunnel junctions and suggests a correlation gap as the origin of the effect.

Findings

Rectification direction and amplitude depend on magnetization alignment.

Small spin-injection currents can switch rectification.

Density of states shows a dip indicating a correlation gap.

Abstract

We have found that the current rectification effect in triple layer (double barrier) (Ga,Mn)As magnetic tunnel junctions strongly depends on the magnetization alignment. The direction as well as the amplitude of the rectification changes with the alignment, which can be switched by bi-directional spin-injection with very small threshold currents. A possible origin of the rectification is energy dependence of the density of states around the Fermi level. Tunneling density of states in (Ga,Mn)As shows characteristic dip around zero-bias indicating formation of correlation gap, the asymmetry of which would be a potential source of the energy dependent density of states.