Year: 2019
Type: article
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 $(\mathcal{PT})$ imaginary potential is added in strongly coupled bilayer lattices and the bound states become strongly localized when the system approaches the exceptional point. As a direct consequence of such $\mathcal{PT}$ 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 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 an alternative way to fabricate quantum device by non-Hermitian impurity.
Authors: K. L. Zhang, X. M. Yang, Z. Song
Institution: Nankai University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: 多体系统量子态的动力学探测制备研究
OpenAlex ID: W2956862037