Multibit Memory Cells Based on Spin-Orbit Torque Driven Magnetization Switching of Nanomagnets with Configurational Anisotropy

In this work, we report the fabrication and characterization of novel four and six terminal current-driven magnetic memory cells. In particular, we experimentally demonstrate the magnetization switching of triangular and square magnets through spin-orbit torque by in-plane currents in a Pt/Ni
₈₁
Fe
₁₉
(Py) heterostructure. The spin torques, generated by applying a constant current in one of multiple Pt wires, are used to switch a Py film between its multiple stable magnetic states, as quantified by anisotropic magnetoresistance (AMR) and tunnel magnetoresistance (TMR) measurements at room temperature. The observations have also been confirmed by micromagnetic simulations.