Chiral filtering in graphene with coupled valleys

TL;DR

This paper explores how valley symmetry breaking in graphene can be used to filter electronic states of specific chirality, potentially enabling valleytronic applications.

Contribution

It introduces a method to control electron transmission in graphene by engineering regions with different valley coupling, revealing new filtering capabilities.

Findings

Valley symmetry breaking enables selective filtering of chiral states.

Different substrate environments induce valley-dependent Hamiltonians.

Potential for designing valleytronic devices using substrate engineering.

Abstract

We analyze the problem of electronic transmission through different regions of a graphene sheet that are characterized by different types of connections between the Dirac points. These valley symmetry breaking Hamiltonians might arise from electronic self-interaction mediated by the dielectric environment of distinct parts of the substrate on which the graphene sheet is placed. We show that it is possible to have situations in which we can use these regions to select or filter states of one desired chirality.