English
Related papers

Related papers: Exceptional points in classical spin dynamics

200 papers

We theoretically study diverse exceptional points (EPs) in an experimentally feasible magno-optomechanics consisting of an optomechanical subsystem coupled to a magnomechanical subsystem via physically direct contact. By adiabatically…

Quantum Physics · Physics 2024-11-14 Wen-Di He , Xiao-Hong Fan , Ming-Yue Liu , Guo-Qiang Zhang , Hai-Chao Li , Wei Xiong

Exotic singular objects, known as exceptional points, are ubiquitous in non-Hermitian physics. They might be spectral singularities in energy bands that produce anomalous effects and defectiveness. The quantum entanglement of a generic…

Quantum Physics · Physics 2023-04-19 Wei-Zhu Yi , Yong-Ju Hai , Rong Xiao , Wei-Qiang Chen

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, the spectral degeneracy points in the complex parameter space, are fundamental to non-Hermitian quantum systems. The dynamics of non-Hermitian systems in the presence of exceptional points differ significantly from those…

Quantum Physics · Physics 2021-01-29 Chon-Fai Kam , Yang Chen

Non-Hermitian systems distinguish themselves from Hermitian systems by exhibiting a phase transition point called an exceptional point (EP), which is the point at which two eigenstates coalesce under a system parameter variation. Many…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 Kun Ding , Guancong Ma , Meng Xiao , Z. Q. Zhang , C. T. Chan

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

Exceptional points (EPs) in non-Hermitian photonics offer singular sensitivity enhancements but have thus far been realized almost exclusively in spatially engineered platforms with fixed geometries and limited tunability. Here we extend EP…

The fundamental concept underlying topological phenomena posits the geometric phase associated with eigenstates. In contrast to this prevailing notion, theoretical studies on time-varying Hamiltonians allow for a new type of topological…

Quantum Physics · Physics 2025-11-27 Pengfei Lu , Yang Liu , Qifeng Lao , Teng Liu , Xinxin Rao , Ji Bian , Hao Wu , Feng Zhu , Le Luo

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

Exceptional points (EPs) are special parameter values of a non-Hermitian eigenvalue problem where eigenfunctions corresponding to a multiple eigenvalue coalesce. In optics, EPs are associated with a number of counter-intuitive wave…

Optics · Physics 2019-10-08 Amgad Abdrabou , Ya Yan Lu

The concept of exceptional point (EP) is demonstrated experimentally in the case of a simple mechanical system consisting of two linearized coupled pendulums. Exceptional points correspond to specific values of the system parameters that…

Computational Physics · Physics 2024-02-08 Nicolas Even , Benoit Nennig , Gautier Lefebvre , Emmanuel Perrey-Debain

The physics of topological singularities, namely exceptional points (EPs), has been a key to wide range of intriguing and unique physical effects in non-Hermitian systems. In this context, the mutual interactions among four coupled states…

Optics · Physics 2020-01-01 Sayan Bhattacherjee , Harsh K. Gandhi , Arnab Laha , Somnath Ghosh

The intricate complex eigenvalues of non-Hermitian Hamiltonians manifest as Riemann surfaces in control parameter spaces. At the exceptional points (EPs), the degeneracy of both eigenvalues and eigenvectors introduces noteworthy topological…

Quantum Physics · Physics 2025-09-08 Sen Zhang , Yangyu Huang , Lei Yu , Kaixuan He , Ning Zhou , Dingbang Xiao , Xuezhong Wu , Franco Nori , Hui Jing , Xin Zhou

Quantum physics can be extended into the complex domain by considering non-Hermitian Hamiltonians that are $\mathcal{PT}$-symmetric. These exhibit exceptional points (EPs) where the eigenspectrum changes from purely real to purely imaginary…

Quantum Physics · Physics 2025-06-23 Jia-Jia Wang , Yu-Hong He , Chang-Geng Liao , Rong-Xin Chen , Jacob A. Dunningham

Exceptional points (EPs) determine the dynamics of open quantum systems and cause also PT symmetry breaking in PT symmetric systems. From a mathematical point of view, this is caused by the fact that the phases of the wavefunctions…

Dynamical Systems · Mathematics 2014-04-30 Hichem Eleuch , Ingrid Rotter

Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators, where eigenvalues and eigenvectors coalesce. Recently, open quantum systems have been increasingly explored as EP testbeds due to their natural…

Quantum Physics · Physics 2025-02-18 Jhen-Dong Lin , Po-Chen Kuo , Neill Lambert , Adam Miranowicz , Franco Nori , Yueh-Nan Chen

The amplitude of resonant oscillations in a non-Hermitian environment can either decay or grow in time, corresponding to a mode with either loss or gain. When two coupled modes have a specific difference between their loss or gain, a…

Classical Physics · Physics 2025-11-07 N. J. Lambert , A. Schumer , J. J. Longdell , S. Rotter , H. G. L. Schwefel

As a most important feature of non-Hermitian systems, exceptional points (EPs) lead to a variety of unconventional phenomena and applications. Here, we study a generic model composed of two coupled non-Hermitian qubits, the EPs can be…

Quantum Physics · Physics 2025-02-12 Zigeng Li , Xinyao Huang , Hongyan Zhu , Guofeng Zhang , Fan Wang , Xiaolan Zhong

Open systems with gain and loss, described by non-trace-preserving, non-Hermitian Hamiltonians, have been a subject of intense research recently. The effect of exceptional-point degeneracies on the dynamics of classical systems has been…

Quantum Physics · Physics 2019-11-01 M. Naghiloo , M. Abbasi , Yogesh N. Joglekar , K. W. Murch

The defining characteristic of an exceptional point (EP) in the parameter space of a family of operators is that upon encircling the EP eigenstates are permuted. In case one encircles multiple EPs, the question arises how to properly…

Mathematical Physics · Physics 2018-08-29 Eric J. Pap , Daniël Boer , Holger Waalkens