Anomalous skew scattering of plasmons in a Dirac electron fluid

TL;DR

This paper explores how Berry phase effects induce giant asymmetric scattering of plasmons in a Dirac electron fluid, revealing resonances and potential for novel plasmonic devices.

Contribution

It extends hydrodynamic models to include Berry flux effects, demonstrating giant skew scattering and resonances in plasmon behavior in Dirac materials.

Findings

Giant asymmetry in plasmon scattering due to Berry flux

Resonance series from chiral trapped modes

Potential experimental realizations in topological insulators and graphene

Abstract

The Berry phase-related nontrivial electronic band geometries can significantly influence bulk and edge plasmons resulting in their non-reciprocal propagation and opening new opportunities for plasmonics. In the present work, we extend the hydrodynamic framework to describe the scattering of plasmons in a Dirac electron fluid off a circular region with an induced nonzero anomalous Hall response, i.e. a Berry flux target. We demonstrate that the scattering has a giant asymmetry or skewness and exhibits a series of resonances. The latter appears due to a chiral non-topological trapped mode circulating the target. We discuss possible experimental realizations, including the surface of a topological insulator film and graphene irradiated by the circularly polarized beam.