Electric spectroscopy of vortex states and dynamics in magnetic disks
  Spin-polarized radio frequency (RF) currents and RF-Oersted fields resonantly excite a magnetic vortex core confined in a micron-scale soft magnetic disk. In this study, we measured the rectifying voltage spectra caused by the anisotropic magnetoresistance oscillation due to the gyration of the vortex with different polarity and chirality. The measured spectra are presented such that we can determine the vortex properties and strength of the spin torques and Oersted field accurately and directly through analytical calculation. 
Minori Goto, Hiroshi Hata, Akinobu Yamaguchi, Yoshinobu Nakatani,   Takehiro Yamaoka, Yukio Nozaki and Hideki Miyajima
cond-mat.mtrl-sci cond-mat.mes-hall