In-memory direct processing based on nanoscale perpendicular magnetic tunnel junctions

Perpendicular magnetic tunnel junctions (p-MTJs) provide advantages such as infinite endurance, high thermal stability, and fast and low-power switching. They are considered as a promising non-volatile memory device to build non-von Neumann computing paradigms and definitively overcome the power bottleneck. Numerous design proposals have been made for p-MTJ logic, but a few physical realizations have been reported. In this paper, we present the experimental implementation of universal stateful logic gates such as "OR", "AND", and material implication ("IMP") by connecting two nanoscale p-MTJs in parallel. Owing to the voltage dependence of switching probability for the spin transfer torque mechanism, the same structure can be reconfigured to different logic gates with only electrical signals. One single-cycle operation is thus required for all the basic Boolean functions. Such in-memory direct processing has great potential to meet some key requirements such as a high energy/areal efficiency and high speed for future computing hardware.