Electric-field control of the magnetic anisotropy in an ultrathin (Ga,Mn)As/(Ga,Mn)(As,P) bilayer

TL;DR

This study demonstrates electric-field manipulation of magnetic anisotropy in an ultrathin ferromagnetic bilayer, enabling control over magnetic orientation via gate voltage, which could impact spintronic device development.

Contribution

It introduces a method to electrically control magnetic anisotropy in a ferromagnetic bilayer using gate voltage, showing significant anisotropy modulation.

Findings

Uniaxial anisotropy field decreases by a factor of ~4 with gate voltage.

Carrier depletion reduces in-plane anisotropy.

Transition to out-of-plane easy-axis is nearly achieved.

Abstract

We report on the electric control of the magnetic anisotropy in an ultrathin ferromagnetic (Ga,Mn)As/(Ga,Mn)(As,P) bilayer with competing in-plane and out-of-plane anisotropies. The carrier distribution and therefore the strength of the effective anisotropy is controlled by the gate voltage of a field effect device. Anomalous Hall Effect measurements confirm that a depletion of carriers in the upper (Ga,Mn)As layer results in the decrease of the in-plane anisotropy. The uniaxial anisotropy field is found to decrease by a factor ~ 4 over the explored gate-voltage range, so that the transition to an out-of-plane easy-axis configuration is almost reached.