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Γ valley transition metal dichalcogenide moire bands.

ABSTRACT: The valence band maxima of most group VI transition metal dichalcogenide thin films remain at the Γ point all of the way from bulk to bilayer. In this paper, we develop a continuum theory of the moiré minibands that are formed in the valence bands of Γ-valley homobilayers by a small relative twist. Our effective theory is benchmarked against large-scale ab initio electronic structure calculations that account for lattice relaxation. As a consequence of an emergent [Formula: see text] symmetry, we find that low-energy Γ-valley moiré holes differ qualitatively from their K-valley counterparts addressed previously; in energetic order, the first three bands realize 1) a single-orbital model on a honeycomb lattice, 2) a two-orbital model on a honeycomb lattice, and 3) a single-orbital model on a kagome lattice.

SUBMITTER: Angeli M

PROVIDER: S-EPMC7958387 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Γ valley transition metal dichalcogenide moiré bands.

Angeli Mattia M MacDonald Allan H AH MacDonald Allan H AH

Proceedings of the National Academy of Sciences of the United States of America 20210301 10

The valence band maxima of most group VI transition metal dichalcogenide thin films remain at the Γ point all of the way from bulk to bilayer. In this paper, we develop a continuum theory of the moiré minibands that are formed in the valence bands of Γ-valley homobilayers by a small relative twist. Our effective theory is benchmarked against large-scale ab initio electronic structure calculations that account for lattice relaxation. As a consequence of an emergent [Formula: see text] symmetry, w ...[more]

PMID: 33658375

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