Efficient prediction of superlattice and anomalous miniband topology from quantum geometry

Fuente: arXiv
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Main Authors: Crépel, Valentin, Cano, Jennifer
Format: Preprint
Published: 2024
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author Crépel, Valentin
Cano, Jennifer
author_facet Crépel, Valentin
Cano, Jennifer
contents Two dimensional materials subject to long-wavelength modulations have emerged as novel platforms to study topological and correlated quantum phases. In this article, we develop a versatile and computationally inexpensive method to predict the topological properties of materials subjected to a superlattice potential by combining degenerate perturbation theory with the method of symmetry indicators. In the absence of electronic interactions, our analysis provides a systematic rule to find the Chern number of the superlattice-induced miniband starting from the harmonics of the applied potential and a few material-specific coefficients. Our method also applies to anomalous (interaction-generated) bands, for which we derive an efficient algorithm to determine all Chern numbers compatible with a self-consistent solution to the Hartree-Fock equations. Our approach gives a microscopic understanding of the quantum anomalous Hall insulators recently observed in rhombohedral graphene multilayers.
format Preprint
id arxiv_https___arxiv_org_abs_2406_17843
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Efficient prediction of superlattice and anomalous miniband topology from quantum geometry
Crépel, Valentin
Cano, Jennifer
Mesoscale and Nanoscale Physics
Two dimensional materials subject to long-wavelength modulations have emerged as novel platforms to study topological and correlated quantum phases. In this article, we develop a versatile and computationally inexpensive method to predict the topological properties of materials subjected to a superlattice potential by combining degenerate perturbation theory with the method of symmetry indicators. In the absence of electronic interactions, our analysis provides a systematic rule to find the Chern number of the superlattice-induced miniband starting from the harmonics of the applied potential and a few material-specific coefficients. Our method also applies to anomalous (interaction-generated) bands, for which we derive an efficient algorithm to determine all Chern numbers compatible with a self-consistent solution to the Hartree-Fock equations. Our approach gives a microscopic understanding of the quantum anomalous Hall insulators recently observed in rhombohedral graphene multilayers.
title Efficient prediction of superlattice and anomalous miniband topology from quantum geometry
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2406.17843