Driven dynamic mode splitting of the magnetic vortex translational resonance.
A magnetic vortex in a restricted geometry possesses a nondegenerate translational excitation that corresponds to circular motion of its core at a characteristic frequency. For 40-nm thick, micron-sized permalloy elements, we find that the translational-mode microwave absorption peak splits into two peaks that differ in frequency by up to 25% as the driving field is increased. An analysis of micromagnetic equations shows that for large driving fields two stable solutions emerge.
Buchanan
K S
KS
Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Grimsditch
M
M
Fradin
F Y
FY
Bader
S D
SD
Novosad
V
V