Spin-plasmons in topological insulator

TL;DR

This paper investigates spin-plasmon excitations in the surface helical electron liquid of topological insulators, revealing their coupled charge and spin density wave nature due to spin-momentum locking.

Contribution

It provides a theoretical analysis of the properties and internal structure of spin-plasmons in topological insulator surfaces, highlighting their unique coupled charge-spin dynamics.

Findings

Spin-plasmons exhibit coupled charge and spin density waves.

The internal structure of these excitations is characterized.

Spin-momentum locking influences the collective modes.

Abstract

Collective plasmon excitations in a helical electron liquid on the surface of strong three-dimensional topological insulator are considered. The properties and internal structure of these excitations are studied. Due to spin-momentum locking in helical liquid on a surface of topological insulator, the collective excitations should manifest themselves as coupled charge- and spin-density waves.