Room temperature spin-orbit torque switching induced by a topological insulator

TL;DR

This paper demonstrates room temperature spin-orbit torque switching in a topological insulator/ferromagnet bilayer, showing high efficiency and robustness, advancing the potential for practical TI-based spintronic devices.

Contribution

It provides the first demonstration of full SOT switching at room temperature using a TI/ferromagnet heterostructure with high efficiency.

Findings

Room temperature SOT switching achieved in TI/ferromagnet bilayer.

Low current density required for switching.

Effective spin Hall angle significantly larger than heavy metals.

Abstract

Recent studies on the magneto-transport properties of topological insulators (TI) have attracted great attention due to the rich spin-orbit physics and promising applications in spintronic devices. Particularly the strongly spin-moment coupled electronic states have been extensively pursued to realize efficient spin-orbit torque (SOT) switching. However, so far current-induced magnetic switching with TI has only been observed at cryogenic temperatures. It remains a controversial issue whether the topologically protected electronic states in TI could benefit spintronic applications at room temperature. In this work, we report full SOT switching in a TI/ferromagnet bilayer heterostructure with perpendicular magnetic anisotropy at room temperature. The low switching current density provides a definitive proof on the high SOT efficiency from TI. The effective spin Hall angle of TI is determined to be several times larger than commonly used heavy metals. Our results demonstrate the robustness of TI as an SOT switching material and provide a direct avenue towards applicable TI-based spintronic devices.