What Has Been Achieved:
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.
Importance of Achievement:
Our results demonstrate robust charge-spin conversion in TI and provide a direct avenue towards applicable TI-based spintronic devices.
Unique Features of the MIP That Enabled Project:
MBE growth of high quality topological insulator thin films on GaAs substrates.
Publication: Han, J., Richardella, A., Siddiqui, S.A., Finley, J., Samarth, N. and Liu, L. (2017) Room-temperature spin-orbit torque switching induced by a topological insulator. Phys. Rev. Lett. 119, 077702.