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Main Authors: Xiao, Yuhang, Hao, Ning
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2409.10891
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author Xiao, Yuhang
Hao, Ning
author_facet Xiao, Yuhang
Hao, Ning
contents Flat-band systems are of great interest due to their strong electron correlations and unique band geometry. Recent studies have linked the properties of Cooper pairs in flat-band superconductors to the quantum metric. Unlike prior studies primarily focused on quasiparticle fluctuations, in this work, we investigate quantum geometric effects on a collective mode of the order parameter-the Higgs mode. We derive the quantum goemetric Higgs-mode correlation length and investigate whether the nonlinear electromagnetic response of the Higgs mode persists in flat band. It turns out that the quantum metric will replaces energy derivatives, playing a crucial role in third-harmonic generation(THG). We further numerically calculated the correlation length and THG in the Lieb lattice. In contrast to traditional single-band results, Higgs mode fluctuations contribute almost entirely to THG, with the quasiparticle contribution being negligible. This finding provides valuable guidance for detecting Higgs modes in flat-band systems through optical methods and reveals the profound influence of quantum geometry in flat-band systems.
format Preprint
id arxiv_https___arxiv_org_abs_2409_10891
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum Geometric Effects on the Higgs Mode in Flat-band Superconductors
Xiao, Yuhang
Hao, Ning
Superconductivity
Flat-band systems are of great interest due to their strong electron correlations and unique band geometry. Recent studies have linked the properties of Cooper pairs in flat-band superconductors to the quantum metric. Unlike prior studies primarily focused on quasiparticle fluctuations, in this work, we investigate quantum geometric effects on a collective mode of the order parameter-the Higgs mode. We derive the quantum goemetric Higgs-mode correlation length and investigate whether the nonlinear electromagnetic response of the Higgs mode persists in flat band. It turns out that the quantum metric will replaces energy derivatives, playing a crucial role in third-harmonic generation(THG). We further numerically calculated the correlation length and THG in the Lieb lattice. In contrast to traditional single-band results, Higgs mode fluctuations contribute almost entirely to THG, with the quasiparticle contribution being negligible. This finding provides valuable guidance for detecting Higgs modes in flat-band systems through optical methods and reveals the profound influence of quantum geometry in flat-band systems.
title Quantum Geometric Effects on the Higgs Mode in Flat-band Superconductors
topic Superconductivity
url https://arxiv.org/abs/2409.10891