Bulk and surface properties of SmB6

TL;DR

This paper reviews the complex bulk and surface properties of SmB6, a material with intriguing electronic states, emphasizing the influence of crystal growth and unresolved scientific questions.

Contribution

It provides a comprehensive review of experimental findings on SmB6's properties, highlighting recent discoveries and open questions in the field.

Findings

Surface states have been experimentally observed in SmB6.

The role of crystal growth and sample preparation significantly affects properties.

Remaining mysteries include the nature of its topological surface states.

Abstract

Samarium hexaboride crystallizes in a simple cubic structure (space group #221, Pm-3m), but its properties are far from being straightforward. Initially classified as a Kondo insulator born out of its intriguing intermediate valence ground state, SmB6 has been recently predicted to be a strongly correlated topological insulator. The subsequent experimental discovery of surface states has revived the interest in SmB6, and our purpose here is to review the extensive and in many aspects perplexing experimental record of this material. We will discuss both surface and bulk properties of SmB6 with an emphasis on the role of crystal growth and sample preparation. We will also highlight the remaining mysteries and open questions in the field.