Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model

Fuente: arXiv
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Auteur principal: Iskin, M.
Format: Preprint
Publié: 2024
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author Iskin, M.
author_facet Iskin, M.
contents We investigate the impacts of the quantum geometry of Bloch states, specifically through the band-resolved quantum-metric tensor, on Cooper pairing and flat-band superconductivity in a three-dimensional pyrochlore-Hubbard model. First we analyze the low-lying two-body spectrum exactly, and show that the pairing order parameter is uniform in this four-band lattice. This allowed us to establish direct relations between the superfluid weight of a multiband superconductor and ($i$) the effective mass of the lowest-lying two-body branch at zero temperature, ($ii$) the kinetic coefficient of the Ginzburg-Landau theory in proximity to the critical temperature, and ($iii$) the velocity of the low-energy Goldstone modes at zero temperature. Furthermore, we perform a comprehensive numerical analysis of the superfluid weight and Goldstone modes, exploring both their conventional and geometric components at zero temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2403_04270
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model
Iskin, M.
Superconductivity
Quantum Gases
Strongly Correlated Electrons
We investigate the impacts of the quantum geometry of Bloch states, specifically through the band-resolved quantum-metric tensor, on Cooper pairing and flat-band superconductivity in a three-dimensional pyrochlore-Hubbard model. First we analyze the low-lying two-body spectrum exactly, and show that the pairing order parameter is uniform in this four-band lattice. This allowed us to establish direct relations between the superfluid weight of a multiband superconductor and ($i$) the effective mass of the lowest-lying two-body branch at zero temperature, ($ii$) the kinetic coefficient of the Ginzburg-Landau theory in proximity to the critical temperature, and ($iii$) the velocity of the low-energy Goldstone modes at zero temperature. Furthermore, we perform a comprehensive numerical analysis of the superfluid weight and Goldstone modes, exploring both their conventional and geometric components at zero temperature.
title Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model
topic Superconductivity
Quantum Gases
Strongly Correlated Electrons
url https://arxiv.org/abs/2403.04270