Illuminating the dark corridor in graphene: polarization dependence of angle-resolved photoemission spectroscopy on graphene

TL;DR

This study uses polarization-dependent ARPES to reveal the complex electronic structure of graphene, showing that polarization rotation can illuminate previously suppressed features, challenging existing theoretical models.

Contribution

It demonstrates that polarization control in ARPES can uncover hidden electronic features in graphene, highlighting limitations of current theoretical understanding.

Findings

Polarization rotation reveals suppressed electronic features in graphene.

The dark corridor effect persists across low photon energies.

First-principles calculations support experimental observations.

Abstract

We have used s- and p-polarized synchrotron radiation to image the electronic structure of epitaxial graphene near the K-point by angular resolved photoemission spectroscopy (ARPES). Part of the experimental Fermi surface is suppressed due to the interference of photoelectrons emitted from the two equivalent carbon atoms per unit cell of graphene's honeycomb lattice. Here we show that by rotating the polarization vector, we are able to illuminate this 'dark corridor' indicating that the present theoretical understanding is oversimplified. Our measurements are supported by first-principles photoemission calculations, which reveal that the observed effect persists in the low photon energy regime.