Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling
Abstract
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 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.
Keywords
Cite
@article{arxiv.2305.02340,
title = {Nontrivial Quantum Geometry and the Strength of Electron-Phonon Coupling},
author = {Jiabin Yu and Christopher J. Ciccarino and Raffaello Bianco and Ion Errea and Prineha Narang and B. Andrei Bernevig},
journal= {arXiv preprint arXiv:2305.02340},
year = {2024}
}
Comments
submitted on 04/14/2023; close to the published version