  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.
