Interband plasmon polaritons in magnetized charge-neutral graphene

TL;DR

This paper investigates interband graphene plasmon polaritons in charge-neutral graphene under magnetic bias, revealing their existence within narrow absorption bands and tunability via magnetic fields, with implications for optical experiments.

Contribution

It demonstrates the existence and tunability of interband GPPs in magnetized charge-neutral graphene, a topic scarcely explored before.

Findings

Interband GPPs exist in magnetized CNG at zero temperature.

GPPs are tunable by external magnetic fields.

GPPs are supported in narrow absorption bands from Landau level transitions.

Abstract

Studying the collective excitations in charge neutral graphene (CNG) has recently attracted a great interest because of unusual mechanisms of the charge carrier dynamics. The latter can play a crucial role, for instance, for superconducting phases in the periodically strained CNG and the magic angle twisted bilayer graphene or for formation of graphene plasmon polaritons (GPPs) associated with interband transitions due to the strain-induced pseudomagnetic field. Importantly, GPP in CNG can be a tool providing new insights into various intriguing quantum phenomena in CNG via optical experiments. However, interband GPPs in CNG are barely investigated, even in the simplest configurations. Here, we show that magnetically biased single layer CNG (particularly, at zero temperature) can support interband GPPs of both transverse magnetic and transverse electric polarizations. They exist inside the narrow absorption bands originating from the electronic transitions between Landau levels and are tunable by the external magnetic field. We put our study into the context of potential near-field and far-field optical experiments, thus opening the door to the exploration of CNG for optics and nanophotonics.