Anisotropic time-dependent London approach

TL;DR

This paper derives anisotropic London equations considering normal currents and studies their effect on surface impedance and susceptibility in anisotropic superconductors, revealing orientation-dependent phenomena.

Contribution

It introduces a new anisotropic London model incorporating normal currents and analyzes their impact on electromagnetic response in superconductors.

Findings

Surface impedance depends on crystal orientation.

Anisotropic susceptibility varies with field direction.

Sample experiences torque unless aligned with crystal axes.

Abstract

The anisotropic London equations taking into account the normal currents are derived and applied to the problem of the surface impedance in the Meisner state of anisotropic materials. It is shown that the complex susceptibility of anisotropic slab depends on the orientation of the applied microwave field relative to the crystal axes. In particular, the anisotropic sample in the microwave field is subject to a torque, unless the field is directed along with one of the crystal principle axes.