The effect of phase fluctuations on the single-particle properties of the underdoped cuprates

TL;DR

This paper investigates how phase fluctuations of the order parameter in underdoped cuprates influence single-particle fermion properties, revealing a connection to pseudogap phenomena and thermodynamic signatures.

Contribution

It introduces a phenomenological low-energy theory linking phase fluctuations to fermion spectral broadening and pseudogap features in underdoped cuprates.

Findings

Vortex pair unbinding causes spectral broadening.

Phase fluctuations induce pseudogap-like features.

Short coherence length makes phase effects thermodynamically significant.

Abstract

We study the effect of order parameter phase fluctuations on the single-particle properties of fermions in the underdoped cuprate superconductors using a phenomenological low-energy theory. We identify the fermion-phase field coupling as the Doppler-shift of the quasiparticle spectrum induced by the fluctuating superfluid velocity and we calculate the effect of these fluctuations on the fermion self-energy. We show that the vortex pair unbinding near the superconducting transition causes a significant broadening in the fermion spectral function, producing a pseudogap-like feature. We also discuss the specific heat and show that the phase fluctuation effect is visible due to the short coherence length.