Higher vortexability: zero field realization of higher Landau levels

Fuente: arXiv
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Auteurs principaux: Fujimoto, Manato, Parker, Daniel E., Dong, Junkai, Khalaf, Eslam, Vishwanath, Ashvin, Ledwith, Patrick
Format: Preprint
Publié: 2024
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author Fujimoto, Manato
Parker, Daniel E.
Dong, Junkai
Khalaf, Eslam
Vishwanath, Ashvin
Ledwith, Patrick
author_facet Fujimoto, Manato
Parker, Daniel E.
Dong, Junkai
Khalaf, Eslam
Vishwanath, Ashvin
Ledwith, Patrick
contents The rise of moiré materials has led to experimental realizations of integer and fractional Chern insulators in small or vanishing magnetic fields. At the same time, a set of minimal conditions sufficient to guarantee a Abelian fractional state in a flat band were identified, namely "ideal" or "vortexable" quantum geometry. Such vortexable bands share essential features with the lowest Landau level, while excluding the need for more fine-tuned aspects such as flat Berry curvature. A natural and important generalization is to ask if such conditions can be extended to capture the quantum geometry of higher Landau levels, particularly the first (1LL), where non-Abelian states at $ν= 1/2,2/5$ are known to be competitive. The possibility of realizing these states at zero magnetic field , and perhaps even more exotic ones, could become a reality if we could identify the essential structure of the 1LL in Chern bands. In this work, we introduce a precise definition of 1LL quantum geometry, along with a figure of merit that measures how closely a given band approaches the 1LL. We apply the definition to identify two models with 1LL structure -- a toy model of double bilayer twisted graphene and a more realistic model of strained Bernal graphene.
format Preprint
id arxiv_https___arxiv_org_abs_2403_00856
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Higher vortexability: zero field realization of higher Landau levels
Fujimoto, Manato
Parker, Daniel E.
Dong, Junkai
Khalaf, Eslam
Vishwanath, Ashvin
Ledwith, Patrick
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The rise of moiré materials has led to experimental realizations of integer and fractional Chern insulators in small or vanishing magnetic fields. At the same time, a set of minimal conditions sufficient to guarantee a Abelian fractional state in a flat band were identified, namely "ideal" or "vortexable" quantum geometry. Such vortexable bands share essential features with the lowest Landau level, while excluding the need for more fine-tuned aspects such as flat Berry curvature. A natural and important generalization is to ask if such conditions can be extended to capture the quantum geometry of higher Landau levels, particularly the first (1LL), where non-Abelian states at $ν= 1/2,2/5$ are known to be competitive. The possibility of realizing these states at zero magnetic field , and perhaps even more exotic ones, could become a reality if we could identify the essential structure of the 1LL in Chern bands. In this work, we introduce a precise definition of 1LL quantum geometry, along with a figure of merit that measures how closely a given band approaches the 1LL. We apply the definition to identify two models with 1LL structure -- a toy model of double bilayer twisted graphene and a more realistic model of strained Bernal graphene.
title Higher vortexability: zero field realization of higher Landau levels
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2403.00856