Optical valleytronics in gapped graphene

TL;DR

This paper introduces a method to manipulate electron valleys in gapped graphene using circularly polarized light and a metallic resonator, enabling valley-specific trapping and filtering beyond the diffraction limit.

Contribution

It presents a novel scheme for valley-dependent electron control in gapped Dirac systems using optical and resonator techniques, exploiting symmetry breaking.

Findings

Valley-dependent band gap modification by circularly polarized light.

Demonstration of valley-specific electron trapping and filtering.

Potential for nanoscale valleytronic device applications.

Abstract

We propose a scheme to trap and filter electrons, valley dependently, on a scale beyond the diffraction limit, in a gapped Dirac system using a circularly polarized light beam and a microscale metallic resonator. The main mechanism allowing the selection is the valley dependent break of the time reversal symmetry. Indeed in one valley, the light partially closes the already existing gap while it opens it in the other one. This difference in the band structure close to the Dirac points, induces a change in the dynamics of the electrons, leading to a valley router behaviour of the system.