Synchrotron-radiation studies of topological insulators

TL;DR

This paper discusses the use of synchrotron radiation, especially ARPES, to study the unique surface states of topological insulators, highlighting their topological origin and spin textures.

Contribution

It provides an accessible overview of the physics, band structure, and synchrotron-based techniques for studying topological insulators.

Findings

Surface states are topologically protected and exhibit unique spin textures.

Synchrotron radiation techniques effectively probe TI surface states.

ARPES reveals the bulk-boundary correspondence in TIs.

Abstract

Topological insulators (TIs) are a recently discovered class of quantum materials that are currently attracting considerable attention. The most interesting aspect of the TIs is, in fact, not that they are bulk insulators but that their surfaces support localized metallic states with some special properties, among others a characteristic spin texture. Most importantly, the existence of these metallic states is not a a surface property; it is required by the topology of the bulk band structure. This Chapter gives an accessible introduction into the physics and band structure of TI materials and into the study of TIs with synchrotron radiation-based techniques, in particular angle-resolved photoemission spectroscopy (ARPES).