Imaging topological torus lattice from an electron crystal in twisted mono-bilayer graphene

TL;DR

This paper reports the discovery of a topological torus lattice in twisted mono-bilayer graphene, revealing how strong correlations and nontrivial band topology intertwine to produce novel quantum states.

Contribution

It introduces the observation of a topological torus lattice in twisted graphene, demonstrating the encoding of nontrivial topology into an electron crystal influenced by Coulomb interactions.

Findings

Discovery of topological torus lattice in twisted graphene

Charge localization leads to electron crystal formation

Spatially modulated Chern numbers observed

Abstract

A variety of exotic quantum phases of matter have been created by Van der Waals heterostructures. Moreover, these twisted heterostructures provide a feasible way of braiding correlation effect and nontrivial band topology together. Here, through a comprehensive spectrum study, we report the discovery of topological torus lattice in twisted mono-bilayer graphene. The strong Coulomb correlations give rise to an unusual charge localization behavior within the moir\'e supercell, leading to an electron crystal. The nontrivial band topology is encoded into the electron crystal, which would result in spatial modulated Chern numbers, and is evidenced by an emergent topological torus lattice state. Our result illustrates an efficient strategy for entwining and engineering topological physics with a strong electron correlation.