Fermi liquid interactions and the superfluid density in d-wave superconductors

TL;DR

This paper develops a phenomenological Fermi liquid theory for 2D d-wave superconductors, analyzing how quasiparticle interactions influence superfluid density and reconciling experimental observations from penetration depth and photoemission data.

Contribution

It introduces a model that incorporates quasiparticle interactions into superfluid density calculations for d-wave superconductors, addressing deviations from isotropic cases.

Findings

Quasiparticle interactions significantly affect superfluid density.

The model explains doping dependence of superfluid density slope.

Results align with experimental measurements from penetration depth and photoemission.

Abstract

We construct a phenomenological superfluid Fermi liquid theory for a two-dimensional d-wave superconductor on a square lattice, and study the effect of quasiparticle interactions on the superfluid density. Using simple models for the dispersion and the Landau interaction function, we illustrate the deviation of these results from those for the isotropic superfluid. This allows us to reconcile the value and doping dependence of the superfluid density slope at low temperature obtained from penetration depth measurements, with photoemission data on nodal quasiparticles.