Antiferromagnetic Single-layer Spin-Orbit Torque Oscillators

TL;DR

This paper demonstrates how a charge current in a single antiferromagnetic layer can generate tunable self-oscillations and terahertz signals, offering a new approach for designing antiferromagnetic spin-orbit torque oscillators.

Contribution

It introduces a method to excite and control self-oscillations in antiferromagnetic layers using spin-orbit torque in simple structures, with potential terahertz applications.

Findings

Self-oscillations can be sustained and tuned in antiferromagnetic layers.

The anisotropic magnetoresistance converts oscillations into terahertz AC voltage.

A steady-state phase diagram as a function of current and torque is computed.

Abstract

We show how a charge current through a single antiferromagnetic layer can excite and control self-oscillations. Sustained oscillations with tunable amplitudes and frequencies are possible in a variety of geometries using certain classes of non-centrosymmetric materials that exhibit finite dissipative spin-orbit torque. We compute the steady-state phase diagram as a function of the current and spin-orbit torque magnitude. The anisotropic magnetoresistance causes the conversion of the resulting AF oscillations to a terahertz AC output voltage. These findings provide an attractive and novel route to design terahertz antiferromagnetic spin-orbit torque oscillators in simple single-layer structures.