Room-Temperature Spin-Orbit Torque Switching Induced by a Topological Insulator

TLDR

Topological insulators have strongly spin‑momentum coupled surface states, yet previous studies reveal large variability in charge‑spin conversion efficiency and room‑temperature magnetic switching has not been achieved. We demonstrate room‑temperature spin‑orbit torque switching in a TI‑ferrimagnet heterostructure with perpendicular anisotropy, achieving an effective spin Hall angle larger than heavy metals and confirming robust charge‑spin conversion for practical TI spintronic devices.

Abstract

The strongly spin-momentum coupled electronic states in topological insulators (TI) have been extensively pursued to realize efficient magnetic switching. However, previous studies show a large discrepancy of the charge-spin conversion efficiency. Moreover, current-induced magnetic switching with TI can only be observed at cryogenic temperatures. We report spin-orbit torque switching in a TI-ferrimagnet heterostructure with perpendicular magnetic anisotropy at room temperature. The obtained effective spin Hall angle of TI is substantially larger than the previously studied heavy metals. Our results demonstrate robust charge-spin conversion in TI and provide a direct avenue towards applicable TI-based spintronic devices.