Stanene: A Good Platform for Topological Insulator and Topological Superconductor

TL;DR

This paper reviews stanene, a 2D material analogous to graphene, highlighting its potential as a topological insulator with a large gap and as a topological superconductor, with experimental evidence supporting these properties.

Contribution

It provides a comprehensive review of stanene's development as a topological insulator and superconductor, including recent experimental observations and methods for phase tuning.

Findings

Stanene has a large topological gap of 0.3 eV.

Experimental evidence of edge states confirms its topological insulator nature.

Layer-dependent superconductivity in stanene has been experimentally observed.

Abstract

Two dimensional (2D) topological insulators (TIs) and topological superconductors (TSCs) have been intensively studied for recent years due to its great potential for dissipationless electron transportation and fault-tolerant quantum computing, respectively. Here we focus on stanene, the tin analogue of graphene, to give a brief review of its development as a candidate for both 2D TI and TSC. Stanene is proposed to be a TI with a large gap of 0.3 eV, and its topological properties are sensitive to various factors, e.g., the lattice constants, chemical functionalization and layer thickness, which offer various methods for phase tunning. Experimentally, the inverted gap and edge states are observed recently, which are strong evidence for TI. In addition, stanene is also predicted to be a time reversal invariant TSC by breaking inversion symmetry, supporting helical Majorana edge modes. The layer-dependent superconductivity of stanene is recently confirmed by both transport and scanning tunneling microscopy measurements. This review gives a detailed introduction to stanene and its topological properties and some prospects are also discussed.