Time-domain analysis of spin-torque induced switching paths in nanoscale CoFeB/MgO/CoFeB magnetic tunnel junction devices

摘要

We performed thousands of single-shot, real-time measurements of spin-transfer-torque induced switching in nanoscale CoFeB/MgO/CoFeB magnetic tunnel junctions having in-plane magnetizations. Our investigation discovered a variety of switching paths occurring in consecutive, nominally identical switching trials of a single device. By mapping the voltage as a function of time to an effective magnetization angle, we determined that reversal of a single device occurs via a variety of thermally activated paths. Our results show a complex switching behavior that has not been captured by previous observations and cannot be fully explained within the simple macrospin model.