Time-resolved imaging of spin transfer switching: beyond the macrospin concept.
Time-resolved images of the magnetization switching process in a spin transfer structure, obtained by ultrafast x-ray microscopy, reveal the limitations of the macrospin model. Instead of a coherent magnetization reversal, we observe switching by lateral motion of a magnetic vortex across a nanoscale element. Our measurements reveal the fundamental roles played independently by the torques due to charge and spin currents in breaking the magnetic symmetry on picosecond time scales.
Acremann
Y
Y
Stanford Synchrotron Radiation Laboratory, Stanford, California 94309, USA.
Strachan
J P
JP
Chembrolu
V
V
Andrews
S D
SD
Tyliszczak
T
T
Katine
J A
JA
Carey
M J
MJ
Clemens
B M
BM
Siegmann
H C
HC
Stöhr
J
J