Direct observation of spin-torque driven magnetization reversal through nonuniform modes.
We present time-resolved x-ray images with 30 nm spatial and 70 ps temporal resolution, which reveal details of the spatially resolved magnetization evolution in nanoscale samples of various dimensions during reversible spin-torque switching processes. Our data in conjunction with micromagnetic simulations suggest a simple unified picture of magnetic switching based on the motion of a magnetic vortex. With decreasing size of the magnetic element the path of the vortex core moves from inside to outside of the nanoelement, and the switching process evolves from a curled nonuniform to an increasingly uniform mode.
Strachan
J P
JP
Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Chembrolu
V
V
Acremann
Y
Y
Yu
X W
XW
Tulapurkar
A A
AA
Tyliszczak
T
T
Katine
J A
JA
Carey
M J
MJ
Scheinfein
M R
MR
Siegmann
H C
HC
Stöhr
J
J