Orthogonal-Bulk-Spin-Orbit-Torque Device for All-Electrical In-Memory Computing

The development of spin-based in-memory computing (IMC) depends on the efficient and flexible control of magnetic order. Here, an orthogonal-bulk-spin-orbit-torque (OBSOT) device composed of a gradient ferromagnetic multilayer with an engineered magnetic anisotropy (MA) is proposed to realize field-free and area-selective magnetization switching. Because of the in-plane shape MA, either transverse or longitudinal current can induce field-free BSOT switching. Moreover, these two orthogonal currents can selectively drive magnetization switching of a crossing area. A theoretical model is established to reveal OBSOT switching process. Based on one OBSOT unit, a complete set of Boolean logic operations are experimentally implemented with high switching efficiency, paving the way for dense and efficient all-electrical IMC.