Electrical Control of Spin Hall Effect in Pt by Hydrogen Ion Adsorption and Desorption

The manipulation of charge-to-spin current conversion and spin-orbit torque (SOT) is of great interest due to its profound physics and potential applications. Controlling the spin current through the electric field provides a perspective for highly efficient SOT devices. Here, we use H₂O-doped ionic liquid gating to realize the reversible and nonvolatile manipulation of the spin Hall effect of Pt, and the spin Hall angle can be modulated by 48% within an accessible gate voltage range. The increase in the spin Hall angle is demonstrated to be caused by the adsorption of hydrogen ions on the Pt surface and the consequent enhancement of the spin Hall conductivity under positive voltage. Furthermore, the enhancement of the spin Hall angle is beneficial to reduce the critical current density for driving the domain wall motion. These results supply a method for the dynamic control of the charge-to-spin current conversion, which will promote the development of spintronic devices driven by electric fields.