English
Related papers

Related papers: Eigenvalue sensitivity from eigenstate geometry ne…

200 papers

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…

Exceptional points (EPs) are singularities in the parameter space of a non-Hermitian system where eigenenergies and eigenstates coincide. They hold promise for enhancing sensing applications, but this is limited by the divergence of shot…

Optics · Physics 2025-04-07 Xu Zheng , Y. D. Chong

We investigate the impact of quantum noise on non-Hermitian resonators at an exceptional point (EP). The system's irreversible Markovian dynamics is modeled using the Lindblad master equation, which accounts for the incoherent pump,…

Quantum Physics · Physics 2025-01-15 Dmitrii N. Maksimov , Andrey A. Bogdanov

In non-Hermitian physics, high-order exceptional points(HOEPs) with eigenvalues and eigenvectors coalesce are known for their enhanced sensitivity to perturbations. Typically, they exhibit eigenvalue splitting that scales as…

Optics · Physics 2025-12-16 Teng Yin , Hao 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 (EPs) determine the dynamics of open quantum systems and cause also PT symmetry breaking in PT symmetric systems. From a mathematical point of view, this is caused by the fact that the phases of the wavefunctions…

Dynamical Systems · Mathematics 2014-04-30 Hichem Eleuch , Ingrid Rotter

The intricate complex eigenvalues of non-Hermitian Hamiltonians manifest as Riemann surfaces in control parameter spaces. At the exceptional points (EPs), the degeneracy of both eigenvalues and eigenvectors introduces noteworthy topological…

Quantum Physics · Physics 2025-09-08 Sen Zhang , Yangyu Huang , Lei Yu , Kaixuan He , Ning Zhou , Dingbang Xiao , Xuezhong Wu , Franco Nori , Hui Jing , Xin Zhou

Describing the evolution of quantum systems by means of non-Hermitian generators opens a new avenue to explore the dynamical properties naturally emerging in such a picture, e.g. operation at the so-called exceptional points, preservation…

Quantum Physics · Physics 2023-12-01 Javid Naikoo , Ravindra W. Chhajlany , Jan Kolodynski

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

Non-Hermitian systems with exceptional points lead to many intriguing phenomena due to the coalescence of both eigenvalues and corresponding eigenvectors, in comparison to Hermitian systems where only eigenvalues degenerate. In this paper,…

Quantum Physics · Physics 2022-10-05 youneng Guo , Guoyou Wang

Exceptional points (EPs), singularities in non-Hermitian systems where eigenvalues and eigenstates coalesce, exhibit a dramatically enhanced response to perturbations compared to Hermitian degeneracies. This makes them exceptional…

Quantum Physics · Physics 2025-11-24 Shu-Xuan Wang , Zhongbo Yan

Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators, where eigenvalues and eigenvectors coalesce. Recently, open quantum systems have been increasingly explored as EP testbeds due to their natural…

Quantum Physics · Physics 2025-02-18 Jhen-Dong Lin , Po-Chen Kuo , Neill Lambert , Adam Miranowicz , Franco Nori , Yueh-Nan Chen

Exceptional points are special degeneracy points in parameter space that can arise in (effective) non-Hermitian Hamiltonians describing open quantum and wave systems. At an n-th order exceptional point, n eigenvalues and the corresponding…

Quantum Physics · Physics 2024-09-23 Daniel Grom , Julius Kullig , Malte Röntgen , Jan Wiersig

Understanding the extreme sensitivity of the eigenvalues of non-Hermitian Hamiltonians to the boundary conditions is of great importance when analyzing non-Hermitian systems, as it appears generically and is intimately connected to the skin…

Quantum Physics · Physics 2022-09-09 Elisabet Edvardsson , Eddy Ardonne

The dynamics of spontaneous emission of an atomic system is studied in the framework of an open quantum system. The resulting quantum master equation for the atomic system is non hermitian. The generator $\mathcal{L}$ can possess…

Quantum Physics · Physics 2016-03-23 Morag Am-Shallem , Ronnie Kosloff , Nimrod Moiseyev

Exceptional points are spectral degeneracies of non-Hermitian systems where both eigenfrequencies and eigenmodes coalesce. The eigenfrequency sensitivities near an exceptional point are significantly enhanced, whereby they diverge directly…

Computational Physics · Physics 2024-05-14 Felix Binkowski , Julius Kullig , Fridtjof Betz , Lin Zschiedrich , Andrea Walther , Jan Wiersig , Sven Burger

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…

Non-Hermitian systems exhibit a variety of unique features rooted in the presence of exceptional points (EP). The distinct topological structure in the proximity of an EP gives rise to counterintuitive behaviors absent in Hermitian systems,…

Quantum Physics · Physics 2025-05-13 He Zhang , Tong Liu , Zhongcheng Xiang , Kai Xu , Heng Fan , Dongning Zheng

We consider large non-Hermitian $N\times N$ matrices with an additive independent, identically distributed (i.i.d.) noise for each matrix elements. We show that already a small noise of variance $1/N$ completely thermalises the bulk…

Probability · Mathematics 2024-01-12 Giorgio Cipolloni , László Erdős , Joscha Henheik , Dominik Schröder

Unconventional properties of non-Hermitian systems, such as the existence of exceptional points, have recently been suggested as a resource for sensing. The impact of noise and utility in quantum regimes however remains unclear. In this…

Quantum Physics · Physics 2018-10-18 Hoi-Kwan Lau , Aashish A. Clerk