Efficient solution strategy to couple micromagnetic simulations with ballistic transport in magnetic tunnel junctions

TL;DR

This paper introduces an efficient computational method combining micromagnetic simulations with non-equilibrium Green's function algorithms to accurately model magnetization switching in magnetic tunnel junctions, capturing key dynamic behaviors.

Contribution

The study presents a novel, computationally efficient approach to simulate spin-transfer torque-induced switching in magnetic tunnel junctions within a coupled micromagnetic and quantum transport framework.

Findings

Switching times below 4 ns at voltages above 300 mV

Reversal trend in switching time with increasing bias voltage

Observed asymmetry in switching behavior between P to AP and AP to P

Abstract

We present a computationally efficient strategy that allows to simulate magnetization switching driven by spin-transfer torque in magnetic tunnel junctions within a micromagnetic model coupled with a matrix-based non-equilibrium Green's function algorithm. Exemplary simulation for a realistic set of parameters are carried out and show switching times below 4 ns for voltages above 300 mV or around 2*10^{10} A m^{-2} for the P to AP (parallel to anti-parallel) direction. For AP to P switching, a trend-reversal in the switching time is seen i.e. the time for magnetization reversal first decreases with increasing bias voltage but then starts to rise again.