Quantum transport in non-Hermitian impurity array

Abstract

We study the formation of band gap bound states induced by a non-Hermitian impurity embedded in a Hermitian system. We show that a pair of bound states emerges inside the band gap when a parity-time ($\mathcal{P}\mathcal{T}$) imaginary potential is added in a strongly coupled bilayer lattices and the bound states become strongly localized when the system approaches to the exceptional point (EP). As a direct consequence of such $\mathcal{P}\mathcal{T}$ impurity-induced bound states, an impurity array can be constructed and protected by energy gap. The effective Hamiltonian of the impurity array is non-Hermitian Su-Schrieffer-Heeger (SSH) type and hosts Dirac probability-preserving dynamics. We demonstrate the conclusion by numerical simulations for the quantum transport of wave packet in right-angle bends waveguide and $Y$-beam splitter. Our finding provides alternative way to fabricate quantum device by non-Hermitian impurity.

10 pages, 6 figures

References in corpus (25)

• Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
• Classification of topological quantum matter with symmetries
• Nonreciprocal light transmission in parity-time-symmetric whispering-gallery microcavities
• Edge states and topological invariants of non-Hermitian systems
• Complex Extension of Quantum Mechanics
• Pseudo-Hermiticity versus PT Symmetry: The necessary condition for the reality of the spectrum of a non-Hermitian Hamiltonian
• Coherent Perfect Absorbers: Time-reversed Lasers
• PT-symmetry breaking and laser-absorber modes in optical scattering systems
• PT-Symmetric Phonon Laser
• Spectral equivalences, Bethe Ansatz equations, and reality properties in PT-symmetric quantum mechanics
• Exact PT-Symmetry Is Equivalent to Hermiticity
• Non-Hermitian perspective of the band structure in heavy-fermion systems
• PT -symmetric harmonic oscillators
• Exceptional rings in two-dimensional correlated systems with chiral symmetry
• PT symmetric square well
• On Pseudo-Hermitian Hamiltonians and Their Hermitian Counterparts
• Robust and fragile PT-symmetric phases in a tight-binding chain
• Conceptual Problems in Scattering from Localized non-Hermitian Potentials
• Degrees and signatures of broken PT-symmetry in (non-uniform) lattices
• Perfect State Transfer in PT-symmetric Non-Hermitian Networks
• Asymmetric transmission through a flux-controlled non-Hermitian scattering center
• Self-sustained emission in semi-infinite non-Hermitian systems at the exceptional point
• Probability-preserving evolution in a non-Hermitian two-band model
• Simple harmonic oscillation in non-Hermitian SSH chain at exceptional point
• Exceptional point induced lasing dynamics in a non-Hermitian system

Cited by in corpus (8)

• Non-Hermitian Floquet topological phases: Exceptional points, coalescent edge modes, and the skin effect
• Protection of parity-time symmetry in topological many-body systems: non-Hermitian toric code and fracton models
• Current-voltage characteristics of the N-I-PT-symmetric non-Hermitian superconductor junction as a probe of non-Hermitian formalisms
• Non-Hermitian impurities in Dirac systems
• Resonant generation of $p$-wave Cooper pair in non-Hermitian Kitaev chain at exceptional point
• Work statistics in non-Hermitian evolutions with Hermitian endpoints
• Coherent confinement and unidirectional dynamics of a wave packet induced by a non-Hermitian Su-Schrieffer-Heeger segment
• Emulating non-Hermitian dynamics in a finite non-dissipative quantum system