Theory of measurements of electrodynamic properties in anisotropic superconductors in tilted magnetic fields. Part II: high frequency regimes

TL;DR

This paper develops a comprehensive tensor model for high frequency electrodynamics in anisotropic type-II superconductors, accounting for vortex dynamics, flux phenomena, and angular dependencies, with applications to thin film measurements.

Contribution

It introduces a novel tensor-based model for high frequency responses in anisotropic superconductors considering vortex motion and angular effects.

Findings

Derived angular dependence of material properties from response data

Provided expressions for surface impedance in thin film geometry

Demonstrated data analysis methods for anisotropic responses

Abstract

The model for high frequency electrodynamics in anisotropic type-II superconductors in the vortex state is studied considering arbitrary orientations between the applied field, the applied current and the anisotropy axis. An anisotropic treatment is provided for the vortex dynamics, taking into account all the phenomena relevant at high frequency, which include flux flow, pinning and creep. The coupling between vortex motion and high frequency currents is included, providing an entirely tensor model of the electromagnetic response to high frequency fields. Examples of data analysis of angular measurements are presented, showing how to derive the angular dependence of the material properties from the measured anisotropic response. Finally, the expression of the measured angle-dependent surface impedance in the largely used thin film geometry is computed.