Reconfigurable Spin Logics and High-density Multistate Memory in a Single Spin-orbit Torque Device

Abstract: Nonvolatile devices based on the spin-orbit torque (SOT) mechanism are highly suitable for in-memory logic operations. The current objective is to enhance the memory density of memory cells while performing logic operations within the same memory unit. Present study demonstrates that integrating SOT with an out-of-plane magnetic field effectively achieves multiple magnetic states in perpendicularly magnetized heterostructures. This study further explores this approach, experimentally demonstrating reconfigurable logic operations within a single SOT device using W/Pt/Co/AlOxheterostructures. Our results show that multistate tuning by SOT integration with out-of-plane magnetic field enables reconfigurable logic operations, including AND, OR, NOR, NAND, and Always ON, within a single device. Additionally, we found that careful selection of input logic operations allows multiple configurations to achieve the same logic function within a single memory device. To enhance multistate memory density, we proposed and experimentally verified a two-step writing process, achieving the highest reported multistate memory density in SOT-based memory devices. These findings highlight the potential of integrating SOT and magnetic field effects to realize high-density, multifunctional in-memory logic devices.