Structural disorder-driven topological phase transition in noncentrosymmetric BiTeI

TL;DR

This study demonstrates that structural disorder can induce a topological insulating phase in BiTeI, revealing a new pathway for creating topological materials through disorder manipulation.

Contribution

The paper introduces a method to induce topological phases via structural disorder in a trivial insulator, supported by first-principles calculations and analysis of electronic structures.

Findings

Disorder induces a topological insulating phase in BiTeI.

Enhanced crystal-field splitting and spin-orbit interaction lead to band inversion.

Surface states exhibit Dirac cones characteristic of strong topological insulators.

Abstract

We investigate the possibility of using structural disorder to induce a topological phase in a solid state system. Using first-principles calculations, we introduce structural disorder in the trivial insulator BiTeI and observe the emergence of a topological insulating phase. By modifying the bonding environments, the crystal-field splitting is enhanced and the spin-orbit interaction produces a band inversion in the bulk electronic structure. Analysis of the Wannier charge centers and the surface electronic structure reveals a strong topological insulator with Dirac surface states. Finally, we propose a prescription for inducing topological states from disorder in crystalline materials. Understanding how local environments produce topological phases is a key step for predicting disordered and amorphous topological materials.