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Related papers: Parity-Time Symmetry and Exceptional points: A Tut…

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Non-Hermitian theory is a theoretical framework that excels at describing open systems. It offers a powerful tool in the characterization of both the intrinsic degrees of freedom (DOFs) of a system and the interactions with the external…

Quantum Physics · Physics 2024-05-28 Kun Ding , Chen Fang , Guancong Ma

Unconventional $p$-wave magnets (UPMs) with odd-parity spin textures have attracted interest for their zero net magnetization and anisotropic spin-split Fermi surfaces. Here, we explore a non-Hermitian open quantum system composed of a…

Mesoscale and Nanoscale Physics · Physics 2025-08-05 Mohammad Alipourzadeh , Davood Afshar , Yaser Hajati

Parity-time ($\mathcal{PT}$) symmetry, originally conceived for non-Hermitian open quantum systems, has opened an excitingly new avenue for the coherent control of light. By tailoring optical gain and loss in integrated photonic structures,…

Optics · Physics 2019-04-11 Junpeng Hou , Zhitong Li , Qing Gu , Chuanwei Zhang

Many new possibilities to observe and use novel physical effects are discovered at so called exceptional points (EPs). This is done by using parity-time (PT) -symmetric non-Hermitian systems and balancing gains and losses. When combined…

Applied Physics · Physics 2023-03-06 Jianlan Xie , Shaohua Dong , Bei Yan , Yuchen Peng , Jianjun Liu , Chengwei Qiu , Shuangchun Wen

A fundamental axiom of quantum mechanics requires the Hamiltonians to be Hermitian which guarantees real eigen-energies and probability conservation. However, a class of non-Hermitian Hamiltonians with Parity-Time ($\mathcal{PT}$) symmetry…

Quantum Physics · Physics 2019-06-19 Yang Wu , Wenqiang Liu , Jianpei Geng , Xingrui Song , Xiangyu Ye , Chang-Kui Duan , Xing Rong , Jiangfeng Du

Parity-time (PT) symmetry in non-Hermitian optical systems promises distinct optical effects and applications not found in conservative optics. Its counterpart, anti-PT symmetry, subscribes another class of intriguing optical phenomena and…

Optics · Physics 2020-03-26 Heng Fan , Jiayang Chen , Zitong Zhao , Jianming Wen , Yuping Huang

The exceptional point, known as the non-Hermitian degeneracy, has special topological structure, leading to various counterintuitive phenomena and novel applications, which are refreshing our cognition of quantum physics. One particularly…

Quantum Physics · Physics 2021-05-05 Wenquan Liu , Yang Wu , Chang-Kui Duan , Xing Rong , Jiangfeng Du

The exotic physics emerging at singularities has long attracted intense theoretical and experimental attention. In non-Hermitian systems, exceptional points (EPs), unique spectral singularities, have given rise to a host of intriguing wave…

Optics · Physics 2026-04-14 Kai Bai , Chen Lin , Jia-Zheng Li , Meng Xiao

Exceptional points (EPs) are central to non-Hermitian physics because of their unique properties and broad application prospects. While extensively studied in parity-time ($\mathcal{P}\mathcal{T}$)-symmetric systems and under Markovian…

Optics · Physics 2026-01-15 H. Z. Shen , X. C. Zhang , L. Y. Ning , Zhi-Guang Lu , Yan-Hui Zhou , Cheng Shang

Exceptional points (EPs) are distinct characteristics of non-Hermitian Hamiltonians that have no counterparts in Hermitian systems. In this study, we focus on EPs in continuous systems rather than discrete non-Hermitian systems, which are…

Quantum Physics · Physics 2025-05-13 Y. T. Wang , R. Wang , X. Z. Zhang

Non-Hermitian systems with anti-parity-time ($\mathcal{APT}$) symmetry have revealed rich physics beyond conventional systems. Here, we study optomechanics in an $\mathcal{APT}$-symmetric spinning resonator and show that, by tuning the…

Quantum Physics · Physics 2023-03-29 Meiyu Peng , Huilai Zhang , Qian Zhang , Tian-Xiang Lu , Imran M. Mirza , Hui Jing

Effective non-Hermitian Hamiltonians are obtained to describe coherent perfect absorbing and lasing boundary conditions. PT -symmetry of the Hamiltonians enables to design configurations which perfectly absorb at multiple frequencies.…

Classical Physics · Physics 2017-04-19 V. Achilleos , G. Theocharis , O. Richoux , V. Pagneux

Parity-time ($PT$)-symmetric Hamiltonians exhibit non-unitary dynamical evolution while maintaining real spectra, and offer unique approaches to quantum sensing and entanglement generation. Here we present a method for simulating the…

Quantum Physics · Physics 2026-01-15 Maryam Abbasi , Koray Aydogan , Anthony W. Schlimgen , Kade Head-Marsden

Recent progress on nonlinear properties of parity-time ($\cal PT$-) symmetric systems is comprehensively reviewed in this article. $\cal PT$ symmetry started out in non-Hermitian quantum mechanics, where complex potentials obeying $\cal PT$…

Pattern Formation and Solitons · Physics 2016-07-20 Vladimir V. Konotop , Jianke Yang , Dmitry A. Zezyulin

The continuous advancements in ultrafast lasers, characterized by high pulse energy, great average power, and ultrashort pulse duration, have opened up new frontiers and applications in various fields such as high-energy-density science. In…

In this paper, we study the interactions of electromagnetic waves with a non-dispersive dynamic medium that is temporally dependent. Electromagnetic fields under material time-modulation conserve their momentum but not their energy. We…

Optics · Physics 2023-07-19 Theodoros T. Koutserimpas , Romain Fleury

In this paper, we experimentally demonstrate a non-Hermitian open PT-symmetric terahertz metasurface comprising complementary plasmonic structures capable of exhibiting an exceptional point (EP). The metasurface consists of two resonators…

Optics · Physics 2025-06-24 Anshul Bhardwaj , Maidul Islam , Chandan Kumar , Anuraj Panwar , Gagan Kumar

Parity-Time (PT) symmetric quantum mechanics is a complex extension of conventional Hermitian quantum mechanics in which physical observables possess a real eigenvalue spectrum. However, an experimental demonstration of the true quantum…

Quantum systems governed by non-Hermitian Hamiltonians with $\PT$ symmetry are special in having real energy eigenvalues bounded below and unitary time evolution. We argue that $\PT$ symmetry may also be important and present at the level…

High Energy Physics - Theory · Physics 2021-03-30 Carl M Bender , Alexander Felski , S P Klevansky , Sarben Sarkar

We study a topological band degeneracy in non-Hermitian systems with parity-time ($PT$) and parity-particle-hole ($CP$) symmetries. In $d$-dimensional non-Hermitian systems, it is shown that $(d-1)$-dimensional exceptional surfaces can…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 Ryo Okugawa , Takehito Yokoyama