Theory of measurements of electrodynamic properties in anisotropic superconductors in tilted magnetic fields. Part I: flux flow and Campbell regimes

TL;DR

This paper develops a theoretical framework for measuring electrodynamic properties of anisotropic superconductors in tilted magnetic fields, focusing on flux flow and Campbell regimes, and provides formulas to relate experimental data to intrinsic material parameters.

Contribution

It introduces tensor-based models for vortex parameters and resistivities, and clarifies how experimental measurements relate to intrinsic anisotropic properties.

Findings

Derived tensor forms for vortex parameters and resistivities.

Provided explicit formulas linking measured and intrinsic quantities.

Discussed applicability of scaling laws to tensor quantities.

Abstract

The vortex dynamics of uniaxial anisotropic superconductors in magnetic fields applied with arbitrary orientation is theoretically studied. Focus is on the model for electrical transport experiments in the linear regime. Relevant vortex parameters, like the viscous drag, the vortex mobility and pinning constant (with point pins), together with the flux flow and Campbell resistivities, are derived in tensor form, in the very different free flux flow and pinned Campbell regimes. The applicability to the various tensor quantities of the well-known scaling laws for the angular dependence on the field orientation is commented. Moreover, it is shown that the experiments do not generally yield the intrinsic values of the anisotropic viscosity and pinning constant. Explicit expressions relating measured and intrinsic quantities are given.