Quantum Transport Simulation of Tunneling Based Spin Torque Transfer (STT) Devices: Design Trade offs and Torque Efficiency

We present a quantum transport simulation of tunneling based spin torque transfer (STT) devices using the non equilibrium Green´s function (NEGF) formalism in the ballistic regime. We show that it is possible to achieve a quantitative agreement for both the tunneling magneto resistance (TMR) and the amplitude of the switching current with the same set of parameters. We also analyze the device performance as a function of parameter variations. Comparison with experiment shows that there is a lot of scope for improving the interface between the magnetic contact and the tunneling oxide, which, in turn, will improve the device performance significantly.