Superconducting fluctuations and charge-4$e$ plaquette state at strong coupling
Abstract
We apply the static auxiliary field Monte Carlo approach to study phase correlations of the pairing fields in a microscopic model with spin-singlet pairing interaction. We find that the short- and long-range phase correlations are well captured by the phase mutual information, which allows us to construct a theoretical phase diagram containing the uniform -wave superconducting region, the phase fluctuating region, the local pairing region, and the disordered region. We show that the gradual development of phase coherence has a number of consequences on spectroscopic measurements, such as the development of the Fermi arc and the anisotropy in the angle-resolved spectra, scattering rate, entropy, specific heat, and quasiparticle dispersion, in good agreement with experimental observations. For strong coupling, our Monte Carlo simulation reveals an unexpected charge-4 plaquette state with -wave bonds, which competes with the uniform -wave superconductivity and exhibits a U-shaped density of states.
Cite
@article{arxiv.2301.08550,
title = {Superconducting fluctuations and charge-4$e$ plaquette state at strong coupling},
author = {Qiong Qin and Jian-Jun Dong and Yutao Sheng and Dongchen Huang and Yi-feng Yang},
journal= {arXiv preprint arXiv:2301.08550},
year = {2023}
}