Current-induced torques due to compensated antiferromagnets

TL;DR

This paper investigates how current-induced torques affect ferromagnetic magnetization in circuits with compensated antiferromagnets, revealing non-zero torques and distinct phase diagrams compared to ferromagnet-only systems.

Contribution

It demonstrates that current-induced torques are generally non-zero in such systems and provides a microscopic NEGF calculation to support this claim.

Findings

Current-induced torques are non-zero in circuits with compensated antiferromagnets.

The phase diagram of ferromagnet configurations differs qualitatively from ferromagnet-only systems.

Symmetry considerations influence the form of the current-induced torque.

Abstract

We analyse the influence of current induced torques on the magnetization configuration of a ferromagnet in a circuit containing a compensated antiferromagnet. We argue that these torques are generically non-zero and support this conclusion with a microscopic NEGF calculation for a circuit containing antiferromagnetic NiMn and ferromagnetic Co layers. Because of symmetry dictated differences in the form of the current-induced torque, the phase diagram which expresses the dependence of ferromagnet configuration on current and external magnetic field differs qualitatively from its ferromagnet-only counterpart.