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Superconductivity in the two-dimensional Hubbard model with cellular dynamical mean-field theory: a quantum impurity model analysis

Authors :
Walsh, C.
Charlebois, M.
Sémon, P.
Tremblay, A. -M. S.
Sordi, G.
Source :
Phys. Rev. B 108, 075163 (2023)
Publication Year :
2023

Abstract

Doping a Mott insulator gives rise to unconventional superconducting correlations. Here we address the interplay between d-wave superconductivity and Mott physics using the two-dimensional Hubbard model with cellular dynamical mean-field theory on a $2\times2$ plaquette. Our approach is to study superconducting correlations from the perspective of a cluster quantum impurity model embedded in a self-consistent bath. At the level of the cluster, we calculate the probabilities of the possible cluster electrons configurations. Upon condensation we find an increased probability that cluster electrons occupy a four-electron singlet configuration, enabling us to identify this type of short-range spin correlations as key to superconducting pairing. The increased probability of this four-electron singlet comes at the expense of a reduced probability of a four-electron triplet with no significant probability redistribution of fluctuations of charges. This allows us to establish that superconductivity at the level of the cluster primarily involves a reorganisation of short-range spin correlations rather than charge correlations. We gain information about the bath by studying the spectral weight of the hybridization function. Upon condensation, we find a transfer of spectral weight leading to the opening of a superconducting gap. We use these insights to interpret the signatures of superconducting correlations in the density of states of the system and in the zero-frequency spin susceptibility.<br />Comment: 19 pages, 10 figures; accepted version

Details

Database :
arXiv
Journal :
Phys. Rev. B 108, 075163 (2023)
Publication Type :
Report
Accession number :
edsarx.2307.02681
Document Type :
Working Paper
Full Text :
https://doi.org/10.1103/PhysRevB.108.075163