Classical phase fluctuations in d-wave superconductors

TL;DR

This paper investigates how low-energy quasiparticles influence phase fluctuations in 2D d-wave superconductors, showing disorder effects justify using a classical XY-model at low temperatures.

Contribution

It demonstrates that disorder removes singularities in phase fluctuations, validating the classical XY-model approach for describing low-temperature behavior.

Findings

Disorder eliminates singularities in phase-only action at T→0.

Classical XY-model is justified for phase fluctuations in disordered d-wave superconductors.

Low-energy quasiparticles significantly affect phase fluctuation dynamics.

Abstract

We study the effects of low-energy nodal quasiparticles on the classical phase fluctuations in a two-dimensional d-wave superconductor. The singularities of the phase-only action at T\to 0 are removed in the presence of disorder, which justifies using an extended classical XY-model to describe phase fluctuations at low temperatures.