Superflow in d-wave superconductors

TL;DR

This paper investigates superflow in d-wave high-temperature superconductors using a gauge-invariant BCS model, analyzing how superfluid velocity affects various physical properties across different anisotropies and doping levels.

Contribution

It provides a comprehensive, gauge-invariant analysis of superflow in d-wave superconductors beyond linear response, including effects of anisotropy and doping.

Findings

Superfluid velocity significantly influences gap functions and critical currents.

Anisotropies from dispersion, order parameter symmetry, and lattice distortions affect superflow.

Results extend understanding of supercurrent behavior in high-Tc superconductors.

Abstract

Superflow in a phenomenological tight-binding model for the superconducting state of some High-temperature superconductors is discussed thoroughly. The formalism used is explicitly gauge-invariant and currents are computed exactly within BCS theory, going therefore beyond linear response theory. The dependence of gap functions, current density, critical currents, and free energy as a function of superfluid velocity for different angles and doping concentrations is investigated. Different sources of anisotropy, like the dispersion relation of the model, the internal symmetry of the order parameter, and orthorhombic distortions of the lattice are also studied.