Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling

Fuente: arXiv
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Autori principali: Yu, Jiabin, Ciccarino, Christopher J., Bianco, Raffaello, Errea, Ion, Narang, Prineha, Bernevig, B. Andrei
Natura: Preprint
Pubblicazione: 2023
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author Yu, Jiabin
Ciccarino, Christopher J.
Bianco, Raffaello
Errea, Ion
Narang, Prineha
Bernevig, B. Andrei
author_facet Yu, Jiabin
Ciccarino, Christopher J.
Bianco, Raffaello
Errea, Ion
Narang, Prineha
Bernevig, B. Andrei
contents The coupling of electrons to phonons (electron-phonon coupling) is crucial for the existence of various phases of matter, in particular superconductivity and density waves. Here, we devise a theory that incorporates the quantum geometry of the electron bands into the electron-phonon coupling, demonstrating the crucial contributions of the Fubini-Study metric or its orbital selective version to the dimensionless electron-phonon coupling constant. We apply the theory to two materials, graphene and MgB$_2$ where the geometric contributions account for approximately 50\% and 90\% of the total electron-phonon coupling constant, respectively. The quantum geometric contributions in the two systems are further bounded from below by topological contributions. Our results suggest that the nontrivial electron band geometry/topology might favor superconductivity with relatively high critical temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2305_02340
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling
Yu, Jiabin
Ciccarino, Christopher J.
Bianco, Raffaello
Errea, Ion
Narang, Prineha
Bernevig, B. Andrei
Superconductivity
Mesoscale and Nanoscale Physics
Materials Science
The coupling of electrons to phonons (electron-phonon coupling) is crucial for the existence of various phases of matter, in particular superconductivity and density waves. Here, we devise a theory that incorporates the quantum geometry of the electron bands into the electron-phonon coupling, demonstrating the crucial contributions of the Fubini-Study metric or its orbital selective version to the dimensionless electron-phonon coupling constant. We apply the theory to two materials, graphene and MgB$_2$ where the geometric contributions account for approximately 50\% and 90\% of the total electron-phonon coupling constant, respectively. The quantum geometric contributions in the two systems are further bounded from below by topological contributions. Our results suggest that the nontrivial electron band geometry/topology might favor superconductivity with relatively high critical temperature.
title Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling
topic Superconductivity
Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2305.02340