Oscillatory spin-orbit torque switching induced by field-like torques

TL;DR

This paper demonstrates a novel oscillatory spin-orbit torque switching method by controlling domain wall dynamics, enabling unipolar deterministic switching in ultrathin magnets, which advances the efficiency and simplicity of magnetic state control.

Contribution

It introduces an incoherent SOT switching scheme that achieves oscillatory behavior through domain wall control, a significant departure from traditional bipolar SOT switching methods.

Findings

Achieved oscillatory switching using domain wall dynamics.

Large field-like torque influences domain wall chirality.

Demonstrated unipolar deterministic switching with nanosecond pulses.

Abstract

Deterministic magnetization switching using spin-orbit torque (SOT) has recently emerged as an efficient means to electrically control the magnetic state of ultrathin magnets. The SOT switching still lacks in oscillatory switching characteristics over time, therefore, it is limited to bipolar operation where a change in polarity of the applied current or field is required for bistable switching. The coherent rotation based oscillatory switching schemes cannot be applied to SOT because the SOT switching occurs through expansion of magnetic domains. Here, we experimentally achieve oscillatory switching in incoherent SOT process by controlling domain wall dynamics. We find that a large field-like component can dynamically influence the domain wall chirality which determines the direction of SOT switching. Consequently, under nanosecond current pulses, the magnetization switches alternatively between the two stable states. By utilizing this oscillatory switching behavior we demonstrate a unipolar deterministic SOT switching scheme by controlling the current pulse duration.