Spin Hall Effect in Topological Insulators

The giant spin Hall effect (SHE) in topological insulators (TIs) is very attractive for applications to various spintronic devices, notably spin-orbit torque magnetoresistive random-access memory (SOT-MRAM). In this paper, we review the recent progress on the giant SHE in TIs, with emphasis on the role of topological surface states. We discuss current challenges and future prospects for TIs as a realistic material in SOT-MRAM.