Electrostatic Charge Fractionalization and Unconventional Superconductivity in Strained Monolayer Graphene

TL;DR

This paper explores how uniaxial strain in monolayer graphene creates flat bands and induces phenomena like charge fractionalization and unconventional superconductivity, offering a controllable platform for correlated electronic phases.

Contribution

It demonstrates that strained monolayer graphene can host flat bands and correlated phases similar to twisted bilayer systems, providing a simpler, tunable alternative.

Findings

Presence of flat, sublattice-polarized bands under strain

Pinning of Fermi level to van Hove singularity

Observation of inhomogeneous charge density waves at fractional fillings

Abstract

Two-dimensional systems with flat bands support correlated phases such as superconductivity and charge fractionalization. While twisted moire systems like twisted bilayer graphene have revealed such states, they remain complex to control. Here, we study monolayer graphene under uniaxial periodic strain, which forms a 1D moire and hosts two flat, sublattice-polarized bands. It is shown that this system exhibits features akin to its twisted counterparts, such as a pinning of the Fermi level to the van Hove singularity and unconventional superconductivity. We also found inhomogeneous charge density waves for rational fractional fillings of the unit cell