English
Related papers

Related papers: Dual-state control of lasing and absorption via co…

200 papers

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 exploit balancing the complex optical energy between scattering and guiding states at contrived exceptional points of degeneracy in order to form an active waveguide without utilizing an active medium. This study reports peculiar…

Optics · Physics 2020-01-03 Shahram Moradi

In a recent work, Y.D. Chong et al. [Phys. Rev. Lett. {\bf 105}, 053901 (2010)] proposed the idea of a coherent perfect absorber (CPA) as the time-reversed counterpart of a laser, in which a purely incoming radiation pattern is completely…

Quantum Physics · Physics 2015-05-19 Stefano Longhi

We report an all-lossy index-guided dual-core photonic crystal fiber (PCF) that hosts a second-order exceptional point (EP) in the systems parameter space. By appropriately selecting a parametric encirclement scheme around the EP, the…

Optics · Physics 2025-03-06 Shamba Ghosh , Arpan Roy , Bishnu P. Pal , Somnath Ghosh

We present an all-fiber emitter-cavity quantum electrodynamics (QED) system which consists of two two-level emitters and a nanofiber cavity. Our scheme makes it possible to observe the higher-order exceptional points based on the coupling…

Quantum Physics · Physics 2022-01-12 Zigeng Li , Xiaomiao Li , Xiaolan Zhong

We analyze the time-domain dynamics of resonators supporting exceptional points (EPs), at which both the eigenfrequencies and the eigenmodes associated with perfect capture of an input wave coalesce. We find that a time-domain signature of…

Optics · Physics 2022-10-18 Asaf Farhi , Ahmed Mekawy , Andrea Alu , Douglas Stone

Exceptional points (EPs), i.e. branch point singularities of non-Hermitian Hamiltonians, are ubiquitous in optics. So far, the signatures of EPs have been mostly studied assuming classical light. In the passive parity-time ($\mathcal{PT}$)…

Quantum Physics · Physics 2018-12-11 Stefano Longhi

Exceptional points (EPs), arising in non-Hermitian systems, have garnered significant attention in recent years, enabling advancements in sensing, wave manipulation, and mode selectivity. However, their role in quantum systems, particularly…

Quantum Physics · Physics 2026-01-21 Chenghe Yu , Mingsheng Tian , Ningxin Kong , Matteo Fadel , Xinyao Huang , Qiongyi He

Physical systems with gain and loss can be described by a non-Hermitian Hamiltonian, which is degenerated at the exceptional points (EPs). Many new and unexpected features have been explored in the non-Hermitian systems with a great deal of…

Exceptional points (EP) in non-Hermitian systems have been widely investigated due to their enhanced sensitivity in comparison to standard systems. In this letter, we report the observation of higher-order pseudo-Hermitian degeneracies in…

Applied Physics · Physics 2023-05-02 Ke Yin , Xianglin Hao , Yuangen Huang , Jianlong Zou , Xikui Ma , Tianyu Dong

Exceptional points (EPs), the degeneracy point of non-Hermitian systems, have recently attracted great attention after its ability to greatly enhance the sensitivity of micro-cavities is demonstrated experimentally. Unlike the usual…

Quantum Physics · Physics 2021-08-04 Geng-Li Zhang , Di Liu , Xi-Ming Wang , Man-Hong Yung

We show theoretically and numerically that mode-locking is feasible with a coupled-cavity system with gain and loss, notably, without any natural saturable absorber. We highlight that in the vicinity of the exceptional point, system $Q$…

Optics · Physics 2023-09-13 Riku Imamura , Shun Fujii , Ayata Nakashima , Takasumi Tanabe

Recent studies have demonstrated that a laser can self-generate frequency combs when tuned near an exceptional point (EP), where two cavity modes coalesce. These EP combs induce periodic modulation of the population inversion in the gain…

Optics · Physics 2025-05-23 Xingwei Gao , Hao He , Weng W. Chow , Alexander Cerjan , Chia Wei Hsu

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…

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

We study coherent perfect absorption (CPA) of light in a Kerr nonlinear metal-dielectric composite medium, illuminated from the opposite ends. Elementary symmetry considerations reveal that equality of the incident light intensities is a…

Optics · Physics 2015-06-16 K. Nireekshan Reddy , S. Dutta Gupta

Realizing efficient and controlled state transfer is necessary for implementing a wide range of classical and quantum information protocols. Recent studies have demonstrated that both asymmetric and symmetric state transfer can be achieved…

Quantum Physics · Physics 2025-10-13 Qi-Cheng Wu , Yu-Liang Fang , Yan-Hui Zhou , Jun-Long Zhao , Yi-Hao Kang , Qi-Ping Su , Chui-Ping Yang

Achieving superradiant lasing with an ultranarrow linewidth is crucial for enhancing atomic clock stability in quantum precision measurement. By employing the exceptional point (EP) property of the system, we demonstrate theoretically…

Quantum Physics · Physics 2026-02-24 Min Du , Qian Bin , Qing-Yang Qiu , Franco Nori , Xin-You Lü

This study explores exceptional points (EPs) in photonic crystals (PhCs) and introduces a novel method for their single-shot observation. Exceptional points are spectral singularities found in non-Hermitian systems, such as leaky PhC slabs.…

Non-Hermitian systems have attracted significant interest because of their intriguing and useful properties, including exceptional points (EPs), where eigenvalues and the corresponding eigenstates of non-Hermitian operators become…

Quantum Physics · Physics 2025-03-28 Hamed Ghaemi-Dizicheh , Shahram Dehdashti , Andreas Hanke , Ahmed Touhami , Janis Nötzel