Moiré Band Engineering in Twisted Trilayer WSe2

Fuente: arXiv
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Autores principales: Nakatsuji, Naoto, Kawakami, Takuto, Tateishi, Hayato, Kato, Koichiro, Koshino, Mikito
Formato: Preprint
Publicado: 2025
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author Nakatsuji, Naoto
Kawakami, Takuto
Tateishi, Hayato
Kato, Koichiro
Koshino, Mikito
author_facet Nakatsuji, Naoto
Kawakami, Takuto
Tateishi, Hayato
Kato, Koichiro
Koshino, Mikito
contents We present a systematic theoretical study on the structural and electronic properties of twisted trilayer transition metal dichalcogenide (TMD) WSe$_2$, where two independent moiré patterns form between adjacent layers. Using a continuum approach, we investigate the optimized lattice structure and the resulting energy band structure, revealing fundamentally different electronic behaviors between helical and alternating twist configurations. In helical trilayers, lattice relaxation induces $αβ$ and $βα$ domains, where the two moiré patterns shift to minimize overlap, while in alternating trilayers, $αα'$ domains emerge with aligned moiré patterns. A key feature of trilayer TMDs is the summation of moiré potentials from the top and bottom layers onto the middle layer, effectively doubling the potential depth. In helical trilayers, this mechanism generates a Kagome lattice potential in the $αβ$ domains, giving rise to flat bands characteristic of Kagome physics. In alternating trilayers, the enhanced potential confinement forms deep triangular quantum wells, distinct from those found in bilayer systems. Furthermore, we demonstrate that a moderate perpendicular electric field can switch the layer polarization near the valence band edge, providing an additional degree of tunability. In particular, it enables tuning of the hybridization between orbitals on different layers, allowing for the engineering of diverse and controllable electronic band structures. Our findings highlight the unique role of moiré potential summation in trilayer systems, offering a broader platform for designing moiré-based electronic and excitonic phenomena beyond those achievable in bilayer TMDs.
format Preprint
id arxiv_https___arxiv_org_abs_2504_20449
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Moiré Band Engineering in Twisted Trilayer WSe2
Nakatsuji, Naoto
Kawakami, Takuto
Tateishi, Hayato
Kato, Koichiro
Koshino, Mikito
Mesoscale and Nanoscale Physics
We present a systematic theoretical study on the structural and electronic properties of twisted trilayer transition metal dichalcogenide (TMD) WSe$_2$, where two independent moiré patterns form between adjacent layers. Using a continuum approach, we investigate the optimized lattice structure and the resulting energy band structure, revealing fundamentally different electronic behaviors between helical and alternating twist configurations. In helical trilayers, lattice relaxation induces $αβ$ and $βα$ domains, where the two moiré patterns shift to minimize overlap, while in alternating trilayers, $αα'$ domains emerge with aligned moiré patterns. A key feature of trilayer TMDs is the summation of moiré potentials from the top and bottom layers onto the middle layer, effectively doubling the potential depth. In helical trilayers, this mechanism generates a Kagome lattice potential in the $αβ$ domains, giving rise to flat bands characteristic of Kagome physics. In alternating trilayers, the enhanced potential confinement forms deep triangular quantum wells, distinct from those found in bilayer systems. Furthermore, we demonstrate that a moderate perpendicular electric field can switch the layer polarization near the valence band edge, providing an additional degree of tunability. In particular, it enables tuning of the hybridization between orbitals on different layers, allowing for the engineering of diverse and controllable electronic band structures. Our findings highlight the unique role of moiré potential summation in trilayer systems, offering a broader platform for designing moiré-based electronic and excitonic phenomena beyond those achievable in bilayer TMDs.
title Moiré Band Engineering in Twisted Trilayer WSe2
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2504.20449