English

Sliding Luttinger Liquid and Topological Flat Bands in Symmetry Mismatched Moir\'e Interfaces

Mesoscale and Nanoscale Physics 2025-06-03 v2

Abstract

In this work we analyze a class of Moir\'e 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 Moir\'e potentials. We then consider two explicit symmetry-mismatched Moir\'e 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 C3C_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.

Keywords

Cite

@article{arxiv.2412.17973,
  title  = {Sliding Luttinger Liquid and Topological Flat Bands in Symmetry Mismatched Moir\'e Interfaces},
  author = {Abhijat Sarma},
  journal= {arXiv preprint arXiv:2412.17973},
  year   = {2025}
}

Comments

Added a figure and two appendices, and additional discussion on the $C_3$ model