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Related papers: Unitary Scattering Protected by Pseudo-Hermiticity

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The spectral singularity (SS) from a non-Hermitian potential is one of the most remarkable scattering feature of non-Hermitian quantum mechanics. At the spectral singular point, the scattering amplitudes diverge to infinite. This phenomena…

Quantum Physics · Physics 2019-10-17 Mohammad Hasan , Bhabani Prasad Mandal

This paper shows that the skin effect in systems of non-Hermitian subwavelength resonators is robust with respect to random imperfections in the system. The subwavelength resonators are highly contrasting material inclusions that resonate…

Mathematical Physics · Physics 2023-08-14 Habib Ammari , Silvio Barandun , Bryn Davies , Erik Orvehed Hiltunen , Ping Liu

In the global framework of quantum theory the individual quantum systems seem clearly separated into two families with the respective manifestly Hermitian and hiddenly Hermitian operators of their Hamiltonian. In the light of certain…

Quantum Physics · Physics 2018-05-15 Miloslav Znojil

In study of pseudo(quasi)-hermitian operators, the key role is played by the positive-definite metric operator. It enables physical interpretation of the considered systems. In the article, we study the pseudo-hermitian systems with…

Quantum Physics · Physics 2011-11-17 Vit Jakubsky

Non-Hermitian quantum systems exhibit fascinating characteristics such as non-Hermitian topological phenomena and skin effect, yet their studies are limited by the intrinsic difficulties associated with their eigenvalue problems, especially…

Mesoscale and Nanoscale Physics · Physics 2024-01-23 Guang Yang , Yongkang Li , Yongxu Fu , Zhenduo Wang , Yi Zhang

Parity-time (PT) symmetric non-Hermitian Hamiltonians bring about many novel features and interesting applications such as quantum gates faster than those in Hermitian systems, and topological state transfer. The performance of evolutions…

Quantum Physics · Physics 2022-07-20 Ji Bian , Kunxu Wang , Pengfei Lu , Xinxin Rao , Hao Wu , Qifeng Lao , Teng Liu , Yang Liu , Feng Zhu , Le Luo

The spectral singularity (SS) and coherent perfect absorption (CPA) have been extensively studied over the last one and half decade for different non-Hermitian potentials in non-Hermitian standard quantum mechanics (SQM) governed by…

Quantum Physics · Physics 2019-08-06 Mohammad Hasan , Bhabani Prasad Mandal

Using transfer-matrix methods, we investigate the response of a multilayered metamaterial system containing defects to an incident acoustic plane wave at normal or oblique incidence. The transmission response is composed of pass-bands with…

Materials Science · Physics 2018-06-28 D. Psiachos , M. M. Sigalas

The non-Hermitian skin effect (NHSE), an anomalous localization behavior of the bulk states, is an inherently non-Hermitian phenomenon, which can not find a counterpart in Hermitian systems. However, the fragility of NHSE has been revealed…

Quantum Physics · Physics 2024-07-30 Shuai Li , Min Liu , Yue Zhang , Rui Tian , Maksims Arzamasovs , Bo Liu

Describing open quantum systems in terms of effective non-Hermitian Hamiltonians gives rise to non-unitary time evolution. In this paper, we study the impact of non-unitary dynamics on the emergent hydrodynamics in quantum systems with a…

Statistical Mechanics · Physics 2024-10-10 Dylan E. Mahoney , Jonas Richter

Non-Hermitian systems can exhibit unique topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems by studying a non-Hermitian disordered Su-Schrieffer-Heeger model with…

Quantum Physics · Physics 2020-04-15 Dan-Wei Zhang , Ling-Zhi Tang , Li-Jun Lang , Hui Yan , Shi-Liang Zhu

Non-Hermitian systems exhibit many peculiar dynamic behaviors which never showed up in Hermitian systems. The existence of spectral singularity (SS) for a non-Hermitian scattering center provides a lasing mechanism in the context of quantum…

Quantum Physics · Physics 2019-04-11 K. L. Zhang , P. Wang , Z. Song

The paradigm shift of the Hermitian systems into the non-Hermitian regime profoundly modifies the inherent topological property, leading to various unprecedented effects such as the non-Hermitian skin effect (NHSE). In the past decade, the…

Classical Physics · Physics 2023-08-21 Yun-Kai Liu , Pei-Chao Cao , Minghong Qi , Qiang-Kai-Lai Huang , Yu-Gui Peng , Ying Li , Xue-Feng Zhu

The complex eigenenergies and non-orthogonal eigenstates of non-Hermitian systems exhibit unique topological phenomena that cannot appear in Hermitian systems. Representative examples are the non-Hermitian skin effect and exceptional…

Quantum Physics · Physics 2025-12-19 Jung-Wan Ryu , Jae-Ho Han , Chang-Hwan Yi , Hee Chul Park , Moon Jip Park

Non-Hermitian systems can manifest rich static and dynamical properties at their exceptional points (EPs). Here, we identify yet another class of distinct phenomena that is hinged on EPs, namely, the emergence of a series of non-Hermitian…

Quantum Physics · Physics 2025-04-03 Zuo Wang , Liang He

We illustrate that a Hermitian nonlinear optical system consisting of hybridized parametric amplification and second harmonic generation mimics non-Hermitian evolution dynamics. Oscillation damping, evolution to a static steady state, and…

Optics · Physics 2021-01-05 Noah Flemens , Nicolas Swenson , Jeffrey Moses

A non-unitary transformation leading to a Hatano-Nelson problem is performed on an array of equally-spaced optical waveguides. Such transformation produces a non-reciprocal system of waveguides, as the corresponding Hamiltonian becomes…

Optics · Physics 2023-07-17 Ivan Bocanegra , Héctor M. Moya-Cessa

We consider the interaction between the Hermitian world, represented by a real delta-function potential $-\alpha\delta(x)$, and the non-Hermitian world, represented by a PT-symmetric pair of delta functions with imaginary coefficients…

High Energy Physics - Theory · Physics 2009-02-23 H. F. Jones

Open-dissipative systems obeying parity-time ($\mathcal{PT}$) symmetry are capable of demonstrating oscillatory dynamics akin to the conservative systems. In contrast to limit cycle solutions characteristic of nonlinear systems, the…

Mesoscale and Nanoscale Physics · Physics 2021-09-01 I. Chestnov , Y. G. Rubo , A. Nalitov , A. Kavokin

The ease of using optical gain/loss provides a fertile ground for experimental explorations of non-Hermitian (NH) physics. Without gain/loss, can we realize the NH effect in a Hermitian system? The interface between the coupled Hermitian…