Spin manipulation by giant valley-Zeeman spin-orbit field in atom-thick WSe2

The phenomenon originating from spin–orbit coupling provides energy-efficient strategies for spin manipulation and device applications. The broken inversion symmetry interface and the resulting electric field induce a Rashba-type spin–orbit field (SOF), which has been demonstrated to generate spin–orbit torque for data storage applications. In this study, we found that spin flipping can be achieved by the valley-Zeeman SOF in monolayer WSe2 at room temperature, which manifests as a negative magnetoresistance in the vertical spin valve. Quantum transmission calculations based on an effective model near the K valley of WSe2 confirm the precessional spin transport of carriers under the giant SOF, which is estimated to be 650 T. In particular, the valley-Zeeman SOF-induced spin dynamics was demonstrated to be tunable with the layer number and stacking phase of WSe2 as well as the gate voltage, which provides a novel strategy for spin manipulation and can benefit the development of ultralow-power spintronic devices.