Competing Orders and Quantum Phase Fluctuations on the Low-Energy Excitations and Pseudogap Phenomena of Cuprate Superconductors

TL;DR

This paper models low-energy excitations in cuprate superconductors by integrating competing orders, quantum phase fluctuations, and superconductivity, explaining various experimental phenomena such as pseudogaps and quasiparticle spectra.

Contribution

It introduces a comprehensive theoretical framework combining competing orders and quantum phase fluctuations to explain cuprate superconductor behaviors.

Findings

Explains excess subgap quasiparticle density of states.

Accounts for momentum-dependent quasiparticle coherence.

Describes temperature evolution of the energy gap.

Abstract

We investigate the low-energy quasiparticle excitation spectra of cuprate superconductors by incorporating both superconductivity (SC) and competing orders (CO) in the bare Green's function and quantum phase fluctuations in the proper self-energy. Our approach provides consistent explanations for various empirical observations, including the excess subgap quasiparticle density of states, ``dichotomy'' in the momentum-dependent quasiparticle coherence and the temperature-dependent gap evolution, and the presence (absence) of the low-energy pseudogap in hole- (electron-) type cuprates depending on the relative scale of the CO and SC energy gaps.