Current-induced spin torque resonance of a magnetic insulator

TL;DR

This paper demonstrates spin torque-induced magnetization dynamics in magnetic insulators, showing they can surpass Oersted field effects, thus opening new avenues for spintronic device integration.

Contribution

It provides the first experimental observation of spin torque effects in magnetic insulators, expanding the scope of spintronics beyond metallic ferromagnets.

Findings

Spin torque can induce significant magnetization dynamics in magnetic insulators.

Magnetization dynamics in insulators can exceed those caused by Oersted fields.

Potential for integrating insulators into spintronic devices is demonstrated.

Abstract

Pure spin currents transport angular momentum without an associated charge flow. This unique property makes them attractive for spintronics applications, such as torque induced magnetization control in nanodevices that can be used for sensing, data storage, interconnects and logics. Up to now, however, most spin transfer torque studies focused on metallic ferromagnets, while magnetic insulators were largely ignored, in spite of superior magnetic quality factors. Here, we report the observation of spin torque-induced magnetization dynamics in a magnetic insulator. Our experiments show that in ultrathin magnetic insulators the spin torque induced magnetization dynamics can be substantially larger than those generated by the Oersted field. This opens new perspectives for the efficient integration of ferro-, ferri-, and antiferromagnetic insulators into electronic devices.