Helical bound states in the continuum of the edge states in two dimensional topological insulators

Abstract

We study bound states embedded into the continuum of edge states in two-dimensional topological insulators. These states emerge in the presence of a short-range potential of a structural defect coupled to the boundary. In this case the edge states flow around the defect and have two resonances in the local density of states. The bound state in continuum (BIC) arises due to an interference of the resonances when they are close to the degeneracy. We find the condition under which the BIC appears, study the spacial distribution of the electron density, and show that the BIC has a helical structure with an electron current circulating around the defect.

6 pages, 3 figures, to be published in Physics Letters A, typos corrected

References in corpus (6)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Chiral bound states in the continuum
• Electronic states induced by nonmagnetic defects in two-dimensional topological insulators
• Bound states in the continuum: localization of Dirac-like fermions
• Non-magnetic defects in the bulk of two-dimensional topological insulators
• Confining electrons on a topological insulator surface using potentials and a magnetic field

Cited by in corpus (5)

• Unconventional bound states in the continuum from metamaterial induced electron-acoustic plasma waves
• Floquet-surface bound states in the continuum in a resonantly driven 1D tilted defect-free lattice
• Quasi-bound Electron Pairs in Two-Dimensional Materials with a Mexican-Hat Dispersion
• Double-Fano resonance in a two-level quantum system coupled to zigzag Phosphorene nanoribbon
• Freezable bound states in the continuum for time-dependent quantum potentials