Anomalous current-induced spin torques in ferrimagnets near compensation

TL;DR

This paper demonstrates that ferrimagnets near their compensation point exhibit significantly enhanced spin-orbit torques due to negative exchange interaction, offering promising avenues for spintronic applications.

Contribution

It reveals the substantial enhancement of spin-orbit torques in ferrimagnets near compensation, supported by macrospin modeling and experimental data.

Findings

Spin-orbit torques are 9 times larger near compensation point.

Effective field and switching efficiency increase substantially.

Ferrimagnets near compensation are promising for spintronic devices.

Abstract

While current-induced spin-orbit torques (SOTs) have been extensively studied in ferromagnets and antiferromagnets, ferrimagnets have been less studied. Here we report the presence of enhanced spin-orbit torques resulting from negative exchange interaction in ferrimagnets. The effective field and switching efficiency increase substantially as CoGd approaches its compensation point, giving rise to 9 times larger spin-orbit torques compared to that of non-compensated one. The macrospin modelling results also support efficient spin-orbit torques in a ferrimagnet. Our results suggest that ferrimagnets near compensation can be a new route for spin-orbit torque applications due to their high thermal stability and easy current-induced switching assisted by negative exchange interaction.