Spin Vortex Resonance in Non-planar Ferromagnetic Dots
  In planar structures, the vortex resonance frequency changes little as a function of an in-plane magnetic field as long as the vortex state persists. Altering the topography of the element leads to a vastly different dynamic response that arises due to the local vortex core confinement effect. In this work, we studied the magnetic excitations in non-planar ferromagnetic dots using a broadband microwave spectroscopy technique. Two distinct resonance frequency ranges were observed depending on the position of the vortex core controllable by applying a relatively small magnetic field. The micromagnetic simulations are in qualitative agreement with the. experimental results. 
Junjia Ding, Pavel Lapa, Shikha Jain, Trupti Khaire, Sergi Lendinez,   Wei Zhang, Matthias B. Jungfleisch, Christian M. Posa...
cond-mat.mtrl-sci cond-mat.mes-hall