Non-linear Vortex Dynamics and Dissipation at High-amplitude Microwave Drive

In this talk, the description of the vortex dynamics and dissipation at arbitrary value of microwave field amplitude is discussed.
Experimental data of vortex surface resistance in bulk niobium elliptical cavities as a function of frequency, trapped magnetic field value and field amplitude will be presented. Numerical calculations of non-linear vortex dynamics under microwave drive for different pinning landscapes allows to describe the mechanism underneath the electromagnetic field amplitude dependence of the surface resistance due to trapped vortices, pointing to the progressive microwave depinning as the most likely mechanism capable to generate such non-linearities.