Z2 invariant protected bound states in topological insulators

Abstract

We present an exact solution of a modifed Dirac equation for topological insulator in the presence of a hole or vacancy to demonstrate that vacancies may induce bound states in the band gap of topological insulators. They arise due to the Z_2 classification of time-reversal invariant insulators, thus are also topologically-protected like the edge states in the quantum spin Hall effect and the surface states in three-dimensional topological insulators. Coexistence of the in-gap bound states and the edge or surface states in topological insulators suggests that imperfections may affect transport properties of topological insulators via additional bound states near the system boundary.

5 pages, 3 figures, Fig. 3 is replaced

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• Controlling spin polarization of a quantum dot via a helical edge state
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• Impurity scattering in the bulk of topological insulators
• Non-magnetic defects in the bulk of two-dimensional topological insulators
• Scaling of the Integrated Quantum Metric in Disordered Topological Phases
• Ferromagnetic Impurity Induced Majorana Zero Mode in Iron-Based Superconductor
• Electrically controlled crossing of energy levels in quantum dots in two-dimensional topological insulators
• Effective spin dephasing mechanism in confined two-dimensional topological insulators
• Chiral properties of topological-state loops
• Bound-states and polarized charged zero modes in three-dimensional topological insulators induced by a magnetic vortex
• Bound states and local topological phase diagram of classical impurity spins coupled to a Chern insulator
• Effects of the spin-orbital coupling on the vacancy-induced magnetism on the honeycomb lattice
• Unified model for non-Abelian braiding of Majorana and Dirac fermion zero modes
• Optical transitions in two-dimensional topological insulators with point defects
• Quantum spin compass models in 2D electronic topological metasurfaces
• Non-Abelian operation through scattering between chiral Dirac edge modes
• Impurity-induced Mott ring states and Mott zeros ring states in the Hubbard operator formalism
• Designing atomic-scale resistive circuits in topological insulators through vacancy-induced localized modes