Generalized London free energy for high-$T_c$ vortex lattices

TL;DR

This paper extends the London free energy model to account for four-fold anisotropies in tetragonal high-$T_c$ superconductors, aiding the understanding of vortex lattice structures observed in various experiments.

Contribution

It introduces a generalized London free energy incorporating anisotropies from d-wave pairing, providing a new framework for analyzing vortex lattices in tetragonal superconductors.

Findings

Model captures effects of four-fold anisotropy on vortex lattice structure

Provides insights relevant to neutron scattering, STM, Bitter decoration, and $$SR experiments

Facilitates interpretation of experimental data in high-$T_c$ superconductors

Abstract

We generalize the London free energy to include four-fold anisotropies which could arise from d-wave pairing or other sources in a tetragonal material. We use this simple model to study vortex lattice structure and discuss neutron scattering, STM, Bitter decoration and $\mu$SR experiments.