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We demonstrate that a periodic waveguide comprising of uniform lossless segments together with discrete gain and radiating elements supports exceptional points of degeneracy (EPDs). We provide analytical expressions for all possible…

Applied Physics · Physics 2021-06-16 Ahmed F. Abdelshafy , Tarek Mealy , Ehsan Hafezi , Alireza Nikzamir , Filippo Capolino

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

Integration of the next generation of photonic structures with electronic and optical on-chip components requires the development of effective methods for confining and controlling light in subwavelength volumes. Several techniques enabling…

Epsilon-near-zero (ENZ) materials, defined by $ | Re({\epsilon}) | < 1$, enable unique light propagation characteristics, including confinement within sub-wavelength regions. To reduce losses in this regime, materials with both near-zero…

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

We investigate local field enhancement phenomena in subwavelength, {\epsilon}-near-zero (ENZ) slabs that do not exploit Fabry-P\'erot resonances. In particular, we study the linear response of engineered metamaterial slabs of finite…

Exceptional points (EPs), singularities of non-Hermitian physics where complex spectral resonances degenerate, are one of the most exotic features of nonequilibrium open systems with unique properties. For instance, the emission rate of…

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

Plasmonic nanoantennas offer new avenues to manipulate the propagation of light in materials due to their near field enhancement and ultrafast response time. Here we investigate the epsilon-near-zero (ENZ) response in an L-shaped…

Applied Physics · Physics 2026-02-06 Elif Ozturk , Hira Asif , Mehmet Gunay , Mehmet Emre Tasgin , Ramazan Sahin

Exceptional points (EPs) in non-Hermitian systems can give rise to intriguing effects not available in conventional Hermitian systems due to their unusual properties. Using full-wave simulations, we investigate the scattering, absorption,…

Classical Physics · Physics 2024-02-13 Chengzhi Zhang , Shubo Wang

Non-conservative physical systems admit a special kind of spectral degeneracy, known as exceptional point (EP), at which eigenvalues and eigenvectors of the corresponding non-Hermitian Hamiltonian coalesce. Dynamical parametric encircling…

Mesoscale and Nanoscale Physics · Physics 2019-10-21 Alexey Galda , Valerii M. Vinokur

Non-Hermitian systems with their spectral degeneracies known as exceptional points (EPs) have been explored for lasing, controlling light transport, and enhancing a sensor s response. A ring resonator can be brought to an EP by controlling…

Optics · Physics 2023-05-09 Hwaseob Lee , Ali Kecebas , Feifan Wang , Lorry Chang , Sahin K. Ozdemir , Tingyi Gu

Electromagnetic waves propagating, at finite speeds, in conventional wave-guiding structures are reflected by discontinuities and decay in lossy regions. In this Letter, we drastically modify this typical guided-wave behavior by combining…

Optics · Physics 2018-09-12 S. Ali Hassani Gangaraj , Francesco Monticone

We propose an efficient optomechanical mass sensor operating at exceptional points (EPs), non-hermitian degeneracies where eigenvalues of a system and their corresponding eigenvectors simultaneously coalesce. The benchmark system consists…

Mesoscale and Nanoscale Physics · Physics 2019-08-07 P. Djorwé , Y. Pennec , B. Djafari-Rouhani

Exceptional points (EPs) are degeneracies of non-Hermitian operators where, in addition to the eigenvalues, corresponding eigenmodes become degenerate. Classical and quantum photonic systems with EPs have attracted tremendous attention due…

Tailoring the losses of optical systems within the frame of non-Hermitian physics has appeared very fruitful in the last few years. In particular, the description of exceptional points (EPs) with coupled resonators have become widespread.…

Epsilon-near-zero (ENZ) systems exhibit unconventional electromagnetic response close to their zero permittivity regime. Here, we explore the ability of ultrathin ENZ films to modulate the transmission of radiation from an underlying…

Optics · Physics 2026-03-04 Arun Mambra , Ravi Pant , Joy Mitra

Exceptional points (EPs) are exotic degeneracies of non-Hermitian systems, where the eigenvalues and the corresponding eigenvectors simultaneously coalesce in parameter space, and these degeneracies are sensitive to tiny perturbations on…

Exceptional points (EPs) represent a distinct type of spectral singularity in non-Hermitian systems, and intriguing physics concepts have been studied with optical EPs recently. As a system beyond photonics, the mechanical oscillators…

Optics · Physics 2023-02-09 Ning Wu , Kaiyu Cui , Qiancheng Xu , Xue Feng , Fang Liu , Wei Zhang , Yidong Huang

We investigate second harmonic generation, low-threshold multistability, all-optical switching, and inherently nonlocal effects due to the free-electron gas pressure in an epsilon-near-zero (ENZ) metamaterial slab made of cylindrical,…