Polarization Dependence of Optical Transitions in Graphene Nanoribbons

TL;DR

This paper investigates how the polarization of light affects optical transitions in graphene nanoribbons, revealing a dependence linked to their chirality and broken translational symmetry.

Contribution

It introduces a microscopic explanation for polarization dependence of optical transitions in graphene nanoribbons based on chirality and symmetry considerations.

Findings

Optical transition matrix elements depend on light polarization.

Chirality influences the electron wavevector changes during optical processes.

The phenomenon is linked to broken translational symmetry in nanoribbons.

Abstract

The universality of $k$-dependent electron-photon and electron-phonon matrix elements is discussed for graphene nanoribbons and carbon nanotubes. An electron undergoes a change in wavevector in the direction of broken translational symmetry, depending on the light polarization direction. We suggest that this phenomenon originates from a microscopic feature of chirality.