Order parameter fluctuation effects in d-wave BCS superconductors

TL;DR

This paper investigates how order parameter fluctuations in d-wave BCS superconductors influence spectral properties, revealing gap reduction, deformation, and angle-dependent quasiparticle lifetimes as potential pseudogap precursors.

Contribution

It introduces a self-consistent calculation method for fluctuation effects on single-particle properties in d-wave superconductors, highlighting their impact on spectral gap and quasiparticle behavior.

Findings

Fluctuations reduce the spectral gap.

Gap shape is deformed with reduced slope at nodes.

Quasiparticle lifetime varies with angle due to fluctuations.

Abstract

We study order parameter fluctuation effects in the superconducting state as a possible precursor to the pseudogap phenomena. Using a low-energy effective theory in the d-wave BCS model, we self-consistently calculate the single-particle properties. We find that the fluctuations reduce the spectral gap, and the shape of the gap is deformed, showing reduced slope of the gap at the nodes. We also show the angle-dependence of the quasiparticle lifetime due to the fluctuations.