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Related papers: Exceptional-point-like Sensing near Hermitian Crit…

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We investigate a non-Hermitian extension of Kitaev chain by considering imaginary $p$-wave pairing amplitudes. The exact solution shows that the phase diagram consists two phases with real and complex \ Bogoliubov-de-gens spectra,…

Quantum Physics · Physics 2020-08-28 X. M. Yang , Z. Song

Exceptional point degeneracies (EPD) of linear non-Hermitian systems have been recently utilized for hypersensitive sensing. This proposal exploits the sublinear response that the degenerate frequencies experience once the system is…

Exceptional points~(EPs) appear as degeneracies in the spectrum of non-Hermitian matrices at which the eigenvectors coalesce. In general, an EP of order $n$ may find room to emerge if $2(n-1)$ real constraints are imposed. Our results show…

Quantum Physics · Physics 2022-07-29 Sharareh Sayyad , Flore K. Kunst

Exceptional points (EPs) in non-Hermitian photonic systems have attracted considerable research interest due to their singular eigenvalue topology and associated anomalous physical phenomena. These properties enable diverse applications…

Optics · Physics 2025-10-17 Kaiyuan Wang , Qi Jie Wang , Matthew R. Foreman , Yu Luo

Non-orthogonality in non-Hermitian quantum systems gives rise to tremendous exotic quantum phenomena, which can be fundamentally traced back to non-unitarity and is much more fundamental and universal than complex energy spectrum. In this…

Quantum Physics · Physics 2023-11-06 Yue-Yu Zou , Yao Zhou , Li-Mei Chen , Peng Ye

Exceptional points (EPs), branch singularities parameter space of non-Hermitian eigenvalue manifolds, display unique topological phenomena linked to eigenvalue and eigenvector switching: the parameter space states are highly sensitive to…

Mesoscale and Nanoscale Physics · Physics 2024-12-24 K. Ho , S. Perna , S. Wittrock , S. Tsunegi , H. Kubota , S. Yuasa , P. Bortolotti , M. d'Aquino , C. Serpico , V. Cros , R. Lebrun

Exceptional points (EPs) are non-Hermitian degeneracies where eigenvalues and eigenvectors coalesce, giving rise to unusual physical effects across scientific disciplines. The concept of EPs has recently been extended to nonlinear physical…

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

The interplay between topology and quantum criticality has given rise to the notion of symmetry-enriched criticality, which has attracted considerable attention in recent years. In this Letter, we demonstrate that parity time (PT) symmetry…

Quantum Physics · Physics 2026-05-15 Kuang-Hung Chou , Xue-Jia Yu , Po-Yao Chang

Exceptional points (EPs) in non-Hermitian systems give rise to enhanced sensitivity and chiral state transfer, which are important for quantum technologies. Although parameter trajectories encircling EPs can control symmetric and chiral…

Quantum Physics · Physics 2026-03-26 Qi-Cheng Wu , Yan-Hui Zhou , Biao-liang Ye , Tong Liu , Yi-Hao Kang , Qi-Ping Su , Chui-Ping Yang

We investigate the nature of quantum criticality and topological phase transitions near the critical lines obtained for the extended Kitaev chain with next nearest neighbor hopping parameters and non-Hermitian chemical potential. We…

Strongly Correlated Electrons · Physics 2023-07-31 S Rahul , Nilanjan Roy , Ranjith R Kumar , Y R Kartik , Sujit Sarkar

Higher-order exceptional points in non-Hermitian systems have recently been used as a tool to engineer high-sensitivity devices, attracting tremendous attention from multidisciplinary fields. Here, we present a simple yet effective scheme…

Optics · Physics 2022-08-31 Ambaresh Sahoo , Amarendra K. Sarma

Non-Hermitian systems with anti-parity-time ($\mathcal{APT}$) symmetry have revealed rich physics beyond conventional systems. Here, we study optomechanics in an $\mathcal{APT}$-symmetric spinning resonator and show that, by tuning the…

Quantum Physics · Physics 2023-03-29 Meiyu Peng , Huilai Zhang , Qian Zhang , Tian-Xiang Lu , Imran M. Mirza , Hui Jing

We consider non-Hermitian tight-binding one-dimensional Hamiltonians and show that imposing a certain symmetry causes all eigenvalues to pair up and the corresponding eigenstates to coalesce in pairs. This Pairwise Coalescence (PC) is an…

Quantum Physics · Physics 2026-02-26 Yusuf H. Erdogan , Masudul Haque

We have investigated the exceptional points (EPs) which are degeneracies of a non-Hermitian Hamiltonian, in the case that three modes are interacting with each other. Even though the parametric evolution of the modes cannot be uniquely…

Quantum Physics · Physics 2015-05-30 Jung-Wan Ryu , Soo-Young Lee , Sang Wook Kim

Open systems with non-Hermitian degeneracies called exceptional points show a significantly enhanced response to perturbations in terms of large energy splittings induced by a small perturbation. This reaction can be quantified by the…

Quantum Physics · Physics 2023-09-08 Jan Wiersig

In non-Hermitian coulped-resonator networks, the eigenvectors of degenerate eigenmodes may become parallel due to the singularity at so-called Exceptional Points (EP). To exploit the parametric sensitivity at EPs, an important problem is,…

Quantum Physics · Physics 2019-01-31 Re-Bing Wu , Yu Zheng , Qi-Ming Chen , Yu-xi Liu

Non-Hermitian systems have attracted considerable attention for their broad impacts on various physical platforms and peculiar applications. In non-Hermitian systems, both eigenvalues and eigenstates simultaneously coalesce at exceptional…

When sources of energy gain and loss are introduced to a wave-scattering system, the underlying mathematical formulation will be non-Hermitian. This paves the way for the existence of exceptional points, where eigenmodes are linearly…

Analysis of PDEs · Mathematics 2021-03-15 Habib Ammari , Bryn Davies , Erik Orvehed Hiltunen , Hyundae Lee , Sanghyeon Yu

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.…