English
Related papers

Related papers: Exceptional points for resonant states on parallel…

200 papers

We demonstrate the existence of exceptional points of degeneracy (EPD) of periodic eigenstates in non-Hermitian coupled chains of dipolar scatterers. Guided modes supported by these structures can exhibit an EPD in their dispersion diagram…

Optics · Physics 2017-03-22 Mohamed A. K. Othman , Vincenzo Galdi , Filippo Capolino

Higher-order exceptional points (EPs), resulting from non-Hermitian degeneracies, have shown greater advantages in sensitive enhancement than second-order EPs (EP2s). Therefore, seeking higher-order EPs in various quantum systems is…

Quantum Physics · Physics 2021-12-15 Wei Xiong , Zhuanxia Li , Yiling Song , Jiaojiao Chen , Guoqiang Zhang , Mingfeng Wang

Exceptional points (EPs) are spectral degeneracies unique to non-Hermitian systems which underpin phenomena from enhanced sensing to unconventional topology. While disorder is usually viewed as detrimental, it can also drive topological…

Disordered Systems and Neural Networks · Physics 2026-01-28 Xiaoyu Cheng , Tiantao Qu , Yaqing Yang , Jun Chen , Lei Zhang

Distinct from closed quantum systems, non-Hermitian system can have exceptional points (EPs) where both eigenvalues and eigenvectors coalesce. Recently, it has been proposed and demonstrated that EPs can enhance the performance of sensors…

Quantum Physics · Physics 2019-11-05 Mengzhen Zhang , William Sweeney , Chia Wei Hsu , Lan Yang , A. D. Stone , Liang Jiang

Exceptional points are special parameter points in spectra of open quantum systems, at which resonance energies degenerate and the associated eigenvectors coalesce. Typical examples are Rydberg systems in parallel electric and magnetic…

Quantum Physics · Physics 2016-06-28 Matthias Feldmaier , Jörg Main , Frank Schweiner , Holger Cartarius , Günter Wunner

Experiments near the lock-in region in maximally dissipative non-Hermitian systems, e.g., conventional laser gyroscopes near the deadband, have run up against the Petermann limit, where excess noise exactly cancels any scale-factor…

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 study the exceptional point (EP) phenomena in a photonic medium with a complex time-periodic permiitivity, i.e., $\epsilon(t)=\epsilon_o+\epsilon_r*sin(\Omega t+\phi)$. We formulate the Maxwell's equations in a form of first-order…

Optics · Physics 2018-08-29 Neng Wang , Zhao-Qing Zhang , C. T. Chan

Exceptional-point (EP) sensors are characterized by a square-root resonant frequency bifurcation in response to an external perturbation. This has lead numerous suggestions for using these systems for sensing applications. However, there is…

Quantum Physics · Physics 2024-08-14 Hudson A. Loughlin , Vivishek Sudhir

Exceptional point (EP) degeneracies in coupled cavities with gain and loss provide on-chip photonic devices with unconventional features and performance. However, such systems with realistic structures often miss the exact EPs even in…

Optics · Physics 2022-01-26 Kenta Takata , Nathan Roberts , Akihiko Shinya , Masaya Notomi

Non-Hermitian systems can have peculiar degeneracies of eigenstates called exceptional points (EPs). An EP of $n$ degenerate states is said to have order $n$, and higher-order EPs (HEPs) with $n \ge 3$ exhibit intrinsic order-scaling…

Optics · Physics 2026-05-20 Kenta Takata , Adam Mock , Masaya Notomi , Akihiko Shinya

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

Recently, there has been intense research in proposing and developing various methods for constructing high-order exceptional points (EPs) in dissipative systems. These EPs can possess a number of intriguing properties related to, e.g.,…

Quantum Physics · Physics 2021-07-12 Ievgen I. Arkhipov , Fabrizio Minganti , Adam Miranowicz , Franco Nori

Lasing and coherent perfect absorption (CPA) are time-reversed manifestations of non-Hermitian light-matter interactions. While exceptional points (EPs) have been extensively explored for controlling lasing dynamics, their role in the…

Optics · Physics 2026-05-26 Arnab Laha , Somnath Ghosh , Adam Miranowicz , Lin Wu

One of the unique features of non-Hermitian~(NH) systems is the appearance of non-Hermitian degeneracies known as exceptional points~(EPs). The extensively studied defective EPs occur when the Hamiltonian becomes non-diagonalizable. Aside…

Quantum Physics · Physics 2023-12-11 Sharareh Sayyad , Marcus Stalhammar , Lukas Rodland , Flore K. Kunst

Exceptional points (EPs) are special spectral degeneracies of non-Hermitian operators: at the EP, the complex eigenvalues coalesce, i.e., they become degenerate in both their real and imaginary parts. In two-dimensional (2D) photonic…

Optics · Physics 2025-06-17 Luigi Frau , Simone Zanotti , Lydie Ferrier , Dario Gerace , Hai Son Nguyen

An exceptional point is a special point in parameter space at which two (or more) eigenvalues and eigenvectors coincide. The discovery of exceptional points within mechanical and optical systems has uncovered peculiar effects in their…

Quantum Physics · Physics 2025-04-24 C. A. Downing , V. A. Saroka

Exceptional points are complex-valued spectral singularities that lead to a host of intriguing features such as loss-induced transparency - a counterintuitive process in which an increase in the system's overall loss can lead to enhanced…

Quantum Physics · Physics 2021-12-13 Konrad Tschernig , Kurt Busch , Demetrios N. Christodoulides , Armando Perez-Leija

Many novel properties of non-Hermitian systems are found at or near the exceptional points-branch points of complex energy surfaces at which eigenvalues and eigenvectors coalesce. In particular, higher-order exceptional points can result in…

Optics · Physics 2019-02-21 Shubo Wang , Bo Hou , Weixin Lu , Yuntian Chen , Z. Q. Zhang , C. T. Chan

The notion of synthetic dimensions has expanded the realm of topological physics to four dimensional (4D) space lately. In this work, non-Hermiticity is used as a synthetic parameter in PT-symmetric photonic crystals to study the…

Optics · Physics 2020-01-16 Qiang Wang , Kun Ding , Hui Liu , Shining Zhu , C. T. Chan