Hermitian chiral boundary states in non-Hermitian topological insulators

Abstract

Eigenenergies of a non-Hermitian system without parity-time symmetry are complex in general. Here, we show that the chiral boundary states of higher-dimensional (two-dimensional and three-dimensional) non-Hermitian topological insulators without parity-time symmetry can be Hermitian with real eigenenergies under certain conditions. Our approach allows one to construct Hermitian chiral edge and hinge states from non-Hermitian two-dimensional Chern insulators and three-dimensional second-order topological insulators, respectively. Such Hermitian chiral boundary channels have perfect transmission coefficients (quantized values) and are robust against disorders. Furthermore, a non-Hermitian topological insulator can undergo the topological Anderson insulator transition from a topological trivial non-Hermitian metal or insulator to a topological Anderson insulator with quantized transmission coefficients at finite disorders.

10 pages, 6 figures (including Supplemental Materials)

References in corpus (18)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Non-Abelian Anyons and Topological Quantum Computation
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
• Observation of phononic helical edge states in a mechanical 'topological insulator'
• Measuring the Chern number of Hofstadter bands with ultracold bosonic atoms
• The Quantum Spin Hall Effect: Theory and Experiment
• Topological Anderson Insulator
• Weyl Exceptional Rings in a Three-Dimensional Dissipative Cold Atomic Gas
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• Topological Polaritons
• Entanglement Spectrum of a Disordered Topological Chern Insulator
• Universality classes of the Anderson Transitions Driven by non-Hermitian Disorder
• Real space topological invariant and higher-order topological Anderson insulator in two-dimensional non-Hermitian systems
• Disorder-Induced Quantum Phase Transitions in Three-Dimensional Second-Order Topological Insulators
• Robustness of Helical Hinge States of Weak Second-Order Topological Insulators
• Universal Hall conductance scaling in non-Hermitian Chern insulators

Cited by in corpus (3)

• Topological Non-Hermitian skin effect
• Anderson localization transitions in disordered non-Hermitian systems with exceptional points
• Chiral Hinge Transport in Disordered Non-Hermitian Second-Order Topological Insulators