Polarization-sensitive absorption of THz radiation by interacting electrons in chirally stacked multilayer graphene

TL;DR

This paper demonstrates that the absorption of circularly polarized THz radiation by multilayer graphene depends on the radiation's helicity, influenced by electron interactions that modify pseudospin textures and induce topologically distinct states.

Contribution

It reveals a helicity-dependent absorption mechanism in multilayer graphene linked to electron interactions and topological states, advancing understanding of optoelectronic properties in 2D materials.

Findings

Absorption depends on radiation helicity due to pseudospin selection rules.

Electron-electron interactions lead to topologically different broken-symmetry states.

States exhibit Chern numbers and anomalous Hall conductivities.

Abstract

We show that opacity of a clean multilayer graphene flake depends on the helicity of the circular polarized electromagnetic radiation. The effect can be understood in terms of the pseudospin selection rules for the interband optical transitions in the presence of exchange electron-electron interactions which alter the pseudospin texture in momentum space. The interactions described within a semi-analytical Hartree--Fock approach lead to the formation of the topologically different broken--symmetry states characterized by Chern numbers and zero-field anomalous Hall conductivities.