Surface plasmonics of Weyl semimetals

TL;DR

This paper explores how surface states in Weyl semimetals influence their plasmonic behavior, revealing new anisotropic collective modes that could be experimentally detected.

Contribution

It demonstrates that massive surface states and Fermi arcs in Weyl semimetals significantly modify surface plasmon modes, introducing novel anisotropic collective excitations.

Findings

Massive surface states alter Fermi-arc plasmons

New anisotropic plasmonic modes are predicted

Experimental signatures expected in electron-energy loss spectroscopy

Abstract

Smooth interfaces of topological systems are known to host massive surface states along with the topologically protected chiral one. We show that in Weyl semimetals these massive states, along with the chiral Fermi arc, strongly alter the form of the Fermi-arc plasmon, Most saliently, they yield further collective plasmonic modes that are absent in a conventional interfaces. The plasmon modes are completely anisotropic as a consequence of the underlying anisotropy in the surface model and expected to have a clear-cut experimental signature, e.g. in electron-energy loss spectroscopy.