Field-Free Switching of Perpendicular Magnetization through Voltage-Gated Spin-Orbit Torque

We experimentally demonstrate the field-free and ultra-low-power switching of perpendicular magnetization by combination of spin-orbit torque (SOT), exchange bias (EB) and voltage-controlled magnetic anisotropy (VCMA) effect. Field-free SOT switching is achieved with the aid of an inplane exchange bias generated in the perpendicularly magnetized IrMn/CoFeB/MgO structure. By applying a gate voltage of 0.6 V, the SOT switching current can be reduced by 49% (to 6.2 MA/cm
²
). Finally, we successfully demonstrate the prototype of a high-density and ultra-low-power voltagegated spintronic memory by both experiments and simulations.