Photo-induced valley currents in strained graphene

TL;DR

This paper theoretically demonstrates that strain-induced anisotropy in graphene can generate valley-specific currents under normal light illumination, with potential applications in strain-mediated valleytronics.

Contribution

It introduces a theoretical model showing how strain in graphene induces valley currents under illumination, highlighting a new approach for valleytronics.

Findings

Strain causes anisotropy leading to valley currents in graphene.

Valley currents depend on strain parameters and light polarization.

Strain-induced valley currents can surpass intrinsic warping effects at certain photon energies.

Abstract

The theoretical results are presented showing that strain-induced anisotropy of graphene spectrum gives rise to the valley currents under the illumination by normally incident light. The currents of the two graphene valleys are mutually compensated providing zero net electric current. The magnitude and direction of the valley currents are determined by the parameters of strain and light polarization. For not too high photon energy strain-induced valley current exceed that due to intrinsic warping of the graphene spectrum which suggests feasibility of strain-mediated valleytronics.