Interacting Virtual Topological Phases in Defect-Rich 2D Materials

TL;DR

This paper studies the stability of virtual topological phases in defect-rich 2D materials, revealing how electron-electron interactions and vacancy density influence the robustness of these phases, with implications for various materials.

Contribution

It introduces a realistic model linking vacancy density, wave function localization, and interactions to the stability of virtual topological phases in 2D materials.

Findings

Electron-electron interactions degrade topological phase robustness.

Vacancy density affects the localization of topological states.

Single-particle approximations may be invalid in certain regimes.

Abstract

We investigate the robustness of {\it virtual} topological states -- topological phases away from the Fermi energy -- against the electron-electron interaction and band filling. As a case study, we employ a realistic model to investigate the properties of vacancy-driven topological phases in transition metal dichalcogenides (TMDs) and establish a connection between the degree of localization of topological wave functions, the vacancy density, and the electron-electron interaction strength with the topological phase robustness. We demonstrate that electron-electron interactions play a crucial role in degrading topological phases thereby determining the validity of single-particle approximations for topological insulator phases. Our findings can be naturally extended to {\it virtual} topological phases of a wide range of materials.