Multi-scale lattice relaxation in general twisted trilayer graphenes

Fuente: arXiv
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Main Authors: Nakatsuji, Naoto, Kawakami, Takuto, Koshino, Mikito
Format: Preprint
Published: 2023
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author Nakatsuji, Naoto
Kawakami, Takuto
Koshino, Mikito
author_facet Nakatsuji, Naoto
Kawakami, Takuto
Koshino, Mikito
contents We present comprehensive theoretical studies on the lattice relaxation and the electronic structures in general non-symemtric twisted trilayer graphenes. By using an effective continuum model, we show that the relaxed lattice structure forms a patchwork of moiré-of-moiré domains, where a moiré pattern given by layer 1 and 2 and another pattern given by layer 2 and 3 become locally commensurate. The atomic configuration inside the domain exhibits a distinct contrast between chiral and alternating stacks, which are determined by the relative signs of the two twist angles. In the chiral case, the electronic band calculation reveals a wide energy window ($>$ 50 meV) with low density of states, featuring sparsely distributed highly one-dimensional electron bands. These one-dimensional states exhibit a sharp localization at the boundaries between super-moiré domains, and they are identified as a topological boundary state between distinct Chern insulators. The alternating trilayer exhibits a coexistence of the flat bands and a monolayer-like Dirac cone, and it is attributed to the formation of moiré-of-moiré domains equivalent to the mirror-symmetric twisted trilayer graphene.
format Preprint
id arxiv_https___arxiv_org_abs_2305_13155
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Multi-scale lattice relaxation in general twisted trilayer graphenes
Nakatsuji, Naoto
Kawakami, Takuto
Koshino, Mikito
Mesoscale and Nanoscale Physics
We present comprehensive theoretical studies on the lattice relaxation and the electronic structures in general non-symemtric twisted trilayer graphenes. By using an effective continuum model, we show that the relaxed lattice structure forms a patchwork of moiré-of-moiré domains, where a moiré pattern given by layer 1 and 2 and another pattern given by layer 2 and 3 become locally commensurate. The atomic configuration inside the domain exhibits a distinct contrast between chiral and alternating stacks, which are determined by the relative signs of the two twist angles. In the chiral case, the electronic band calculation reveals a wide energy window ($>$ 50 meV) with low density of states, featuring sparsely distributed highly one-dimensional electron bands. These one-dimensional states exhibit a sharp localization at the boundaries between super-moiré domains, and they are identified as a topological boundary state between distinct Chern insulators. The alternating trilayer exhibits a coexistence of the flat bands and a monolayer-like Dirac cone, and it is attributed to the formation of moiré-of-moiré domains equivalent to the mirror-symmetric twisted trilayer graphene.
title Multi-scale lattice relaxation in general twisted trilayer graphenes
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2305.13155