Topological spin-orbit torque in ferrimagnetic Weyl semimetal

Meguro, Tomonari*; Ozawa, Akihiro*; Kobayashi, Koji*; Araki, Yasufumi   ; Nomura, Kentaro*

We theoretically find a topological spin-orbit torque (SOT) in the compensated ferrimagnetic Weyl semimetal TiMnAl. The topological SOT arises from all the occupied states, which is free from dissipation. However, it is negligible in metallic magnets and was not reported in Weyl semimetals. We show the enhancement of the topological SOT from the mixed Berry curvature around the Weyl points in TiMnAl. This finding provides a guiding principle for designing highly efficient SOT devices using the topological nature of ferrimagnetic Weyl semimetals.