Ideal near-Dirac triple-point semimetal in III-V semiconductor alloys

TL;DR

This paper predicts that certain bismuth-doped III-V semiconductor alloys can exhibit ideal near-Dirac triple-point semimetal properties, offering new platforms for topological material research and optoelectronic applications.

Contribution

It identifies specific bismuth-doped III-V alloys as topological semimetals with near-Dirac triple points, expanding the family of experimentally accessible topological materials.

Findings

GaBi and InBi are Dirac-Weyl semimetals.

GaAs0.5Bi0.5, GaSb0.5Bi0.5, InSb0.5Bi0.5 are triple-point semimetals.

These materials are experimentally accessible and suitable for heterostructure studies.

Abstract

Despite the growing interest in topological materials, the difficulty of experimentally synthesizing and integrating them with other materials has been one of the main barriers restricting access to their unique properties. Recent advances in synthesizing metastable phases of crystalline materials can help to overcome this barrier and offer new platforms to experimentally study and manipulate band topology. Because III-V semiconductors have a wide range of functional material applications (including optoelectronic devices, light-emitting diodes, and highly efficient solar cells), and because Bi-doped III-V materials can be synthesized by ion plantation and ion-cutoff methods, we revisit the effect of bismuth substitution in metastable III-V semiconductors. Through first-principles calculation methods, we show that in wurtzite structure III-V materials, Bi substitution can lead to band inversion phenomena and induce nontrivial topological properties. Specifically, we identify that GaBi and InBi are Dirac-Weyl semimetals, characterized by the coexistence of Dirac points and Weyl points, and $\text{GaAs}_{0.5} \text{Bi}_{0.5}$, $\text{GaSb}_{0.5} \text{Bi}_{0.5}$, $\text{InSb}_{0.5} \text{Bi}_{0.5}$ are triple-point semimetals, characterized by two sets of "near Dirac" triple points on the Fermi level. These experimentally-accessible bismuth-based topological semimetals can be integrated into the large family of functional III-V materials for experimental studies of heterostructures and future optoelectronic applications.