Micromagnetic modeling of double spin-torque magnetic tunnel junction devices

Emerging nonvolatile magnetoresistive random access memory exhibits high endurance and long data retention compared to flash memory. Additionally, devices with double spin torque magnetic tunnel junctions (dsMTJ) featuring two magnetic reference layers demonstrate enhanced torques, fast switching, and reduced switching currents. To accurately model these devices, we adopt a coupled spin and charge transport approach allowing to describe spin-transfer torques in metallic spin valves and magnetic tunnel junctions on equal footing. Our findings indicate the critical influence of metallic non-magnetic spacers (NMS) properties separating the free layer from the second reference layer on the switching speed improvement in dsMTJ devices.