Nanowire Spin Torque Oscillator Driven by Spin Orbit Torques

TL;DR

This paper demonstrates that ferromagnetic nanowires can exhibit coherent self-oscillations driven by spin orbit torques, extending the active region dimensions of spin torque oscillators beyond nanoscale sizes.

Contribution

It provides experimental evidence of magnetization self-oscillations in a one-dimensional ferromagnetic system driven by spin orbit torques, expanding the understanding of spin torque oscillator dimensions.

Findings

Coherent self-oscillations observed in ferromagnetic nanowires.

Spin orbit torques can excite self-oscillations in 1D magnetic systems.

Active region size of spin torque oscillators can be extended.

Abstract

Spin torque from spin current applied to a nanoscale region of a ferromagnet can act as negative magnetic damping and thereby excite self-oscillations of its magnetization. In contrast, spin torque uniformly applied to the magnetization of an extended ferromagnetic film does not generate self-oscillatory magnetic dynamics but leads to reduction of the saturation magnetization. Here we report studies of the effect of spin torque on a system of intermediate dimensionality - a ferromagnetic nanowire. We observe coherent self-oscillations of magnetization in a ferromagnetic nanowire serving as the active region of a spin torque oscillator driven by spin orbit torques. Our work demonstrates that magnetization self-oscillations can be excited in a one-dimensional magnetic system and that dimensions of the active region of spin torque oscillators can be extended beyond the nanometer length scale.