Valley polarization braiding in strained graphene

TL;DR

This paper demonstrates how strained graphene in the quantum Hall regime can host valley-polarized edge-like states, with a distinctive braid pattern in local density of states serving as a fingerprint for valley polarization detection.

Contribution

It identifies precise conditions for valley-polarized states in strained graphene and introduces a method to visualize their unique braid pattern.

Findings

Valley-polarized edge-like states can be isolated within Landau gaps.

A unique braid pattern in local density of states indicates valley polarization.

Strain allows flexible positioning of valley-polarized states.

Abstract

Previous works on deformed graphene predict the existence of valley-polarized states, however, optimal conditions for their detection remain challenging. We show that in the quantum Hall regime, edge-like states in strained regions can be isolated in energy within Landau gaps. We identify precise conditions for new conducting edges-like states to be valley polarized, with the flexibility of positioning them at chosen locations in the system. A map of local density of states as a function of energy and position reveals a unique braid pattern that serves as a fingerprint to identify valley polarization.