Robust flat bands in twisted trilayer graphene quasicrystals

Fuente: arXiv
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Auteurs principaux: Hao, Chen-Yue, Zhan, Zhen, Pantaleón, Pierre A., He, Jia-Qi, Zhao, Ya-Xin, Watanabe, Kenji, Taniguchi, Takashi, Guinea, Francisco, He, Lin
Format: Preprint
Publié: 2024
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author Hao, Chen-Yue
Zhan, Zhen
Pantaleón, Pierre A.
He, Jia-Qi
Zhao, Ya-Xin
Watanabe, Kenji
Taniguchi, Takashi
Guinea, Francisco
He, Lin
author_facet Hao, Chen-Yue
Zhan, Zhen
Pantaleón, Pierre A.
He, Jia-Qi
Zhao, Ya-Xin
Watanabe, Kenji
Taniguchi, Takashi
Guinea, Francisco
He, Lin
contents Moiré structures formed by twisting three layers of graphene with two independent twist angles present an ideal platform for studying correlated quantum phenomena, as an infinite set of angle pairs is predicted to exhibit flat bands. Moreover, the two mutually incommensurate moiré patterns among the twisted trilayer graphene (TTG) can form highly tunable moiré quasicrystals. This enables us to extend correlated physics in periodic moiré crystals to quasiperiodic systems. However, direct local characterization of the structure of the moiré quasicrystals and of the resulting flat bands are still lacking, which is crucial to fundamental understanding and control of the correlated moiré physics. Here, we demonstrate the existence of flat bands in a series of TTGs with various twist angle pairs and show that the TTGs with different magic angle pairs are strikingly dissimilar in their atomic and electronic structures. The lattice relaxation and the interference between moiré patterns are highly dependent on the twist angles. Our direct spatial mappings, supported by theoretical calculations, reveal that the localization of the flat bands exhibits distinct symmetries in different regions of the moiré quasicrystals.
format Preprint
id arxiv_https___arxiv_org_abs_2401_09010
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Robust flat bands in twisted trilayer graphene quasicrystals
Hao, Chen-Yue
Zhan, Zhen
Pantaleón, Pierre A.
He, Jia-Qi
Zhao, Ya-Xin
Watanabe, Kenji
Taniguchi, Takashi
Guinea, Francisco
He, Lin
Materials Science
Mesoscale and Nanoscale Physics
Moiré structures formed by twisting three layers of graphene with two independent twist angles present an ideal platform for studying correlated quantum phenomena, as an infinite set of angle pairs is predicted to exhibit flat bands. Moreover, the two mutually incommensurate moiré patterns among the twisted trilayer graphene (TTG) can form highly tunable moiré quasicrystals. This enables us to extend correlated physics in periodic moiré crystals to quasiperiodic systems. However, direct local characterization of the structure of the moiré quasicrystals and of the resulting flat bands are still lacking, which is crucial to fundamental understanding and control of the correlated moiré physics. Here, we demonstrate the existence of flat bands in a series of TTGs with various twist angle pairs and show that the TTGs with different magic angle pairs are strikingly dissimilar in their atomic and electronic structures. The lattice relaxation and the interference between moiré patterns are highly dependent on the twist angles. Our direct spatial mappings, supported by theoretical calculations, reveal that the localization of the flat bands exhibits distinct symmetries in different regions of the moiré quasicrystals.
title Robust flat bands in twisted trilayer graphene quasicrystals
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2401.09010