Single-shot time-domain studies of spin-torque-driven switching in magnetic tunnel junctions

Y. -T. Cui, G. Finocchio, C. Wang, J. A. Katine, R. A. Buhrman, D. C. Ralph

Published 2009-06-13Version 1

We report single-shot measurements of resistance versus time for thermally assisted spin-torque-driven switching in magnetic tunnel junctions. We achieve sufficient sensitivity to resolve the resistance signals leading up to switching, including the variations between individual switching events. Analyses of pre-switching thermal fluctuations allow detailed measurements of coherence times and variations in magnetization precession amplitude. We find that with a small in-plane hard-axis magnetic field the magnetization dynamics are more spatially coherent than for the case of zero field.