Pairing Fluctuations Determine Low Energy Electronic Spectra in Cuprate Superconductors

TL;DR

This paper presents a minimal theory explaining the electronic spectra in cuprate superconductors by considering pairing fluctuations, successfully reproducing ARPES experimental features such as Fermi arcs and pseudogaps.

Contribution

It introduces a theoretical framework that links pairing fluctuations to observable spectral features in cuprates, aligning well with experimental data.

Findings

Reproduces Fermi arcs and pseudogap behavior above T_c

Quantitatively matches ARPES spectral features

Explains gap deviations below T_c

Abstract

We describe here a minimal theory of tight binding electrons moving on the square planar Cu lattice of the hole-doped cuprates and mixed quantum mechanically with pairs of them (Cooper pairs). Superconductivity occurring at the transition temperature T_c is the long-range, d-wave symmetry phase coherence of these Cooper pairs. Fluctuations necessarily associated with incipient long-range superconducting order have a generic large distance behaviour near T_c. We calculate the spectral density of electrons coupled to such Cooper pair fluctuations and show that features observed in Angle Resolved Photo Emission Spectroscopy (ARPES) experiments on different cuprates above T_c as a function of doping and temperature emerge naturally in this description. These include `Fermi arcs' with temperature-dependent length and an antinodal pseudogap which fills up linearly as the temperature increases towards the pseudogap temperature. Our results agree quantitatively with experiment. Below T_c, the effects of nonzero superfluid density and thermal fluctuations are calculated and compared successfully with some recent ARPES experiments, especially the observed `bending' or deviation of the superconducting gap from the canonical d-wave form.