Chiral model of twisted bilayer graphene realized in a monolayer

TL;DR

This paper shows that a monolayer graphene under a specific superlattice potential can replicate the chiral model of twisted bilayer graphene, offering a simpler platform to study its complex physics.

Contribution

It introduces the 'half-chiral model' realized in monolayer graphene and explores its properties, interactions, and potential experimental realizations.

Findings

Mapping of monolayer graphene to the half-chiral model.

Analysis of interacting phases at integer fillings.

Identification of candidate substrates for experimental realization.

Abstract

We demonstrate that a single layer of graphene subject to a superlattice potential nearly commensurate to a $\sqrt{3} \times \sqrt{3}$ supercell exactly maps to the chiral model of twisted bilayer graphene, albeit with half as many degrees of freedom. We comprehensively review the properties of this ``half-chiral model,'' including the interacting phases stabilized at integer fillings and the effects of substrate-induced symmetry breaking. We list candidate substrates that could produce a superlattice potential on graphene with the correct periodicity to access the flat band limit. Experimental measurements on a half-chiral moire heterostructure, in which valley-skyrmions cannot form, could yield insights on the physics they mediate in twisted bilayer graphene.