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Main Author: Sarma, Abhijat
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2412.17973
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author Sarma, Abhijat
author_facet Sarma, Abhijat
contents In this work we analyze a class of Moiré models consisting of an active honeycomb monolayer such as graphene or a hexagonal transition-metal dichalcogenide (TMD) on top of a substrate, in which the K and K' valleys of the active layer are folded near each other by a suitably chosen substrate geometry. Generalizing the so-called ``coupled-valley'' model of Scheer et al. [1], we start from a microscopic tight-binding description, deriving a continuum model from Schrieffer-Wolff perturbation theory and obtaining an effective description of the low-energy momentum states in either valley as well as the explicit microscopic forms of the Moiré potentials. We then consider two explicit symmetry-mismatched Moiré geometries with a rectangular substrate, the first of which displays an emergent time-reversal symmetry as well as a broad parameter regime which displays quasi-1D physics characterized by the existence of a Sliding Luttinger Liquid phase. This model also has a nontrivial topological character, captured by the Berry curvature dipole. The second geometry displays an emergent $C_3$ rotational symmetry despite the rectangular substrate, reducing to a continuum model considered in Ref. [1] that was shown to display honeycomb and Kagome topological flat bands.
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publishDate 2024
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spellingShingle Sliding Luttinger Liquid and Topological Flat Bands in Symmetry Mismatched Moiré Interfaces
Sarma, Abhijat
Mesoscale and Nanoscale Physics
In this work we analyze a class of Moiré models consisting of an active honeycomb monolayer such as graphene or a hexagonal transition-metal dichalcogenide (TMD) on top of a substrate, in which the K and K' valleys of the active layer are folded near each other by a suitably chosen substrate geometry. Generalizing the so-called ``coupled-valley'' model of Scheer et al. [1], we start from a microscopic tight-binding description, deriving a continuum model from Schrieffer-Wolff perturbation theory and obtaining an effective description of the low-energy momentum states in either valley as well as the explicit microscopic forms of the Moiré potentials. We then consider two explicit symmetry-mismatched Moiré geometries with a rectangular substrate, the first of which displays an emergent time-reversal symmetry as well as a broad parameter regime which displays quasi-1D physics characterized by the existence of a Sliding Luttinger Liquid phase. This model also has a nontrivial topological character, captured by the Berry curvature dipole. The second geometry displays an emergent $C_3$ rotational symmetry despite the rectangular substrate, reducing to a continuum model considered in Ref. [1] that was shown to display honeycomb and Kagome topological flat bands.
title Sliding Luttinger Liquid and Topological Flat Bands in Symmetry Mismatched Moiré Interfaces
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2412.17973