Surface Plasmons and Topological Insulators

TL;DR

This paper investigates surface plasmons at interfaces involving topological insulators, revealing a novel magnetic polarization rotation effect that can be observed experimentally, with implications for understanding topological materials.

Contribution

It demonstrates the magnetic polarization rotation of surface plasmons at topological insulator interfaces, extending the understanding of plasmon behavior in topologically non-trivial materials.

Findings

Magnetic polarization of surface plasmons is rotated out of the plane at topological interfaces.

The effect is observable with polarized light excitation.

The phenomenon occurs even with doped topological insulators with bulk carriers.

Abstract

We study surface plasmons localized on interfaces between topologically trivial and topologically non-trivial time reversal invariant materials in three dimensions. For the interface between a metal and a topological insulator the magnetic polarization of the surface plasmon is rotated out of the plane of the interface; this effect should be experimentally observable by exciting the surface plasmon with polarized light. More interestingly, we argue that the same effect also is realized on the interface between vacuum and a doped topological insulator with non-vanishing bulk carrier density.