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Related papers: Unveiling the Self-Orthogonality at Exceptional Po…

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Recent studies on non-Hermitian optical systems having exceptional points (EPs) have revealed a host of unique characteristics associated with these singularities, including unidirectional invisibility, chiral mode switching and laser…

Exceptional points (EPs) with their intriguing spectral topology have attracted considerable attention in a broad range of physical systems, with potential sensing applications driving much of the present research in this field. Here we…

Optics · Physics 2026-01-29 Jan Wingenbach , Stefan Schumacher , Xuekai Ma

Exceptional points (EPs) in anti-parity-time (APT)-symmetric systems have attracted significant interest. While linear APT-symmetric systems exhibit structural similarities with nonlinear dissipative systems, such as mutually…

Optics · Physics 2025-09-03 Takahiro Uemura , Kenta Takata , Masaya Notomi

We analyze a two-dimensional Kondo lattice model with special emphasis on non-Hermitian properties of the single-particle spectrum, following a recent proposal by Kozii and Fu. Our analysis based on the dynamical mean-field theory…

Strongly Correlated Electrons · Physics 2018-08-01 Tsuneya Yoshida , Robert Peters , Norio Kawakami

Exceptional points (EPs) associated with a square-root singularity have been found in many non-Hermitian systems. In most of the studies, the EPs found are isotropic meaning that the same singular behavior is obtained independent of the…

Classical Physics · Physics 2018-08-28 Kun Ding , Guancong Ma , Z. Q. Zhang , C. T. Chan

We present a transmission line theory of exceptional points of degeneracy (EPD) in coupled-mode guiding structures, i.e., a theory that illustrates the characteristics of coupled electromagnetic modes under a special dispersion degeneracy…

Optics · Physics 2017-09-15 Mohamed A. K. Othman , Filippo Capolino

We investigate a scheme for observing the third-order exceptional point (EP3) in an ion-cavity setting. In the lambda-type level configuration, the ion is driven by a pump field, and the resonator is probed with another weak laser field. We…

Quantum Physics · Physics 2023-11-07 Jinuk Kim , Taegyu Ha , Donggeon Kim , Dowon Lee , Ki-Se Lee , Jongcheol Won , Youngil Moon , Moonjoo Lee

Non-Hermitian Hamiltonians describing open systems can feature singularities called exceptional points (EPs). Resonant frequencies become strongly dependent on externally applied perturbations near an EP which has given rise to the concept…

Instrumentation and Detectors · Physics 2020-04-02 Heming Wang , Yu-Hung Lai , Zhiquan Yuan , Myoung-Gyun Suh , Kerry Vahala

A non-Hermitian system at an exceptional point (EP), a specific critical point (CP) associated with the parity-time symmetric phase transition, exhibits a sublinear response to perturbation and promise unprecedented sensitivity beyond the…

Non-Hermitian systems can produce branch singularities known as exceptional points (EPs). Different from singularities in Hermitian systems, the topological properties of an EP can involve either the winding of eigenvalues that produces a…

Quantum Physics · Physics 2021-07-21 Weiyuan Tang , Kun Ding , Guancong Ma

Exceptional points (EPs) are degeneracy of non-Hermitian Hamiltonians, at which the eigenvalues, along with their eigenvectors, coalesce. Their orders are given by the Jordan decomposition. Here, we focus on higher-order EPs arising in…

Quantum Physics · Physics 2023-04-18 Kang Yang , Ipsita Mandal

Spectral degeneracies (dubbed nodal points in momentum space) play fundamental roles in understanding exotic properties of light and matter. In lattice systems, unpaired band-structure degeneracies are subject to well-established no-go…

Mesoscale and Nanoscale Physics · Physics 2026-03-30 Kunkun Wang , J. Lukas K. König , Kang Yang , Lei Xiao , Wei Yi , Emil J. Bergholtz , Peng Xue

Exceptional points (EPs) are singularities in non-Hermitian systems, where the system transmission spectrum varies significantly at the phase transition point. Here, we propose a practical scheme to study the changes of the optomechanically…

Quantum Physics · Physics 2025-12-25 Y. Pan , H. -L. Zhang , Y. -F. Jiao , D. -Y. Wang , S. -L. Su , H. Jing

Exceptional points (EPs) are spectral defects displayed by non-Hermitian systems in which multiple degenerate eigenvalues share a single eigenvector. This distinctive feature makes systems exhibiting EPs more sensitive to external…

Quantum Physics · Physics 2025-12-11 Subhajyoti Bid , Henning Schomerus

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

Exceptional points in an optical dimer of spheres, which have the same size and operate in the spectral region of the dipolar resonance, are considered. By choosing different materials of these spheres, we can offset the radiative loss and…

Optics · Physics 2023-07-31 Alexey A. Dmitriev , Mikhail V. Rybin

Exceptional point (EP) denotes the non-Hermitian degeneracy, in which both eigenvalues and eigenstates become identical. By the conventional local Markovian master equation, EP can be constructed by parity-time (PT) or anti-PT symmetry in a…

Quantum Physics · Physics 2023-08-30 Dong Xie , Chunling Xu

In recent years, particular physical phenomena enabled by non-Hermitian metamaterial systems have attracted significant research interests. In this paper, a non-Hermitian three-dimensional metamaterial near the exceptional point (EP) is…

Applied Physics · Physics 2024-01-24 Yanjie Wu , Ding Zhang , Qiuyu Li , Hai Lin , Xintong Shi , Jie Xiong , Haoquan Hu , Jing Tian , Bian Wu , Y. Liu

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

This paper theoretically and numerically studies the response characteristics of non-Hermitian resonant photonic systems operating near an exceptional point (EP), where two resonant eigenmodes coalesce. It is shown that a system near an EP…

Optics · Physics 2018-04-06 Satoshi Sunada