Topological Materials Discovery By Large-order symmetry indicators

TL;DR

This paper uses symmetry indicators to efficiently discover topological crystalline phases in specific space groups, predicting several new topological materials and Dirac semimetals with potential for studying boundary state interactions.

Contribution

It introduces a method leveraging large-order symmetry indicators to identify topological materials in five space groups, expanding the pool of realistic TCP candidates.

Findings

Predicted multiple TCPs in specific space groups.

Identified new Dirac semimetals with clean Fermi surfaces.

Provided candidate materials for experimental study.

Abstract

Crystalline symmetries play an important role in the classification of band structures, and the rich variety of spatial symmetries in solids leads to various topological crystalline phases (TCPs). However, compared with topological insulators and Dirac/Weyl semimetals, relatively few realistic materials candidates have been proposed for TCPs. Based on our recently developed method for the efficient discovery of topological materials using symmetry indicators, we explore topological materials in five space groups (i.e. SGs87,140,221,191,194), which are indexed by large order strong symmetry based indicators (Z8 and Z12) allowing for the realization of several kinds of gapless boundary states in a single compound. We predict many TCPs, and the representative materials include: Pt3Ge(SG140), graphite(SG194), XPt3 (SG221,X=Sn,Pb), Au4Ti (SG87) and Ti2Sn (SG194). As by-products, we also find that AgXF3 (SG140,X=Rb,Cs) and AgAsX (SG194,X=Sr,Ba) are good Dirac semimetals with clean Fermi surface. The proposed materials provide a good platform to study the novel properties emerging from the interplay between different types of boundary states.