English
Related papers

Related papers: Exceptional Points in Random-Defect Phonon Lasers

200 papers

Exceptional points (EPs), at which more than one eigenvalue and eigenvector coalesce, are unique spectral features of Non-Hermiticity (NH) systems. They exist widely in open systems with complex energy spectra. We experimentally demonstrate…

A novel anti-P-pseudo-Hermitian mechanical system that integrates piezoelectric actuators and sensors with non-reciprocal coupling into mechanical beams is proposed. This configuration enables the system to exhibit programmable exceptional…

Applied Physics · Physics 2026-03-10 Yanzheng Wang , Jianlei Zhao , Qian Wu , Xiaoming Zhou , Heng Jiang , Weiqiu Chen , Mu Wang , Guoliang Huang

Exceptional points (EPs) are degeneracy of non-Hermitian Hamiltonians, at which the eigenvalues, along with their eigenvectors, coalesce. Their orders are given by the Jordan decomposition. Here, we focus on higher-order EPs arising in…

Quantum Physics · Physics 2023-04-18 Kang Yang , Ipsita Mandal

Exceptional points (EPs) are degeneracies of non-Hermitian systems, where both eigenvalues and eigenvectors coalesce. Classical and quantum systems exhibiting high-order EPs have recently been identified as fundamental building blocks for…

With respect to parity-time (PT) symmetry, anti-parity-time (APT) symmetric system exhibits much easier readout mechanism due to its real frequency splitting. Generally, such systems need to be operated at exceptional points (EPs) to obtain…

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

Dissipation usually plays a negative role in quantum metrological technologies, which aim to improve measurement precision by leveraging quantum effects that are vulnerable to environment-induced decoherence. Recently, it has been…

The amplitude of resonant oscillations in a non-Hermitian environment can either decay or grow in time, corresponding to a mode with either loss or gain. When two coupled modes have a specific difference between their loss or gain, a…

Classical Physics · Physics 2025-11-07 N. J. Lambert , A. Schumer , J. J. Longdell , S. Rotter , H. G. L. Schwefel

We have observed the quench of the lasing at the exceptional point in the electronic circuit system by applying asymmetric gain in the coupled oscillator. Since there is the analogy between oscillation in laser and oscilation in the…

Optics · Physics 2016-05-04 Sungmook Kang , Heeso Noh

We identify a new kind of physically realizable exceptional point (EP) corresponding to degenerate coherent perfect absorption, in which two purely incoming solutions of the wave operator for electromagnetic or acoustic waves coalesce to a…

Optics · Physics 2019-03-12 William R. Sweeney , Chia Wei Hsu , Stefan Rotter , A. Douglas Stone

We propose nonreciprocal phonon lasing in a coupled cavity system composed of an optomechanical and a spinning resonator. We show that the optical Sagnac effect leads to significant modifications in both the mechanical gain and the power…

Quantum Physics · Physics 2018-12-19 Y. Jiang , S. Maayani , T. Carmon , Franco Nori , H. Jing

The optical properties of defects in solids produce rich physics, from gemstone coloration to single-photon emission for quantum networks. Essential to describing optical transitions is electron-phonon coupling, which can be predicted from…

Materials Science · Physics 2026-04-21 Mark E. Turiansky , John L. Lyons , Noam Bernstein

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

Exceptional points (EPs) are degenerate singularities in a non-Hermitian system that can be induced by controlling the interaction between resonant photonic modes. EPs can enable unusual optical phenomena and significantly enhance the…

Applied Physics · Physics 2023-09-15 Hoon Yeub Jeong , Yeonsoo Lim , Jungho Han , Soo-Chan An , Young Chul Jun

We propose an analysis technique for the exceptional points (EPs) occurring in the discrete spectrum of open quantum systems (OQS), using a semi-infinite chain coupled to an endpoint impurity as a prototype. We outline our method to locate…

Quantum Physics · Physics 2012-10-16 Savannah Garmon , Ingrid Rotter , Naomichi Hatano , Dvira Segal

Exceptional point (EP) denotes the non-Hermitian degeneracy, in which both eigenvalues and eigenstates become identical. By the conventional local Markovian master equation, EP can be constructed by parity-time (PT) or anti-PT symmetry in a…

Quantum Physics · Physics 2023-08-30 Dong Xie , Chunling Xu

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 (EPs) represent non-Hermitian degeneracies where eigenvalues and eigenvectors coalesce, giving rise to enhanced sensitivity and critically damped dynamics. We demonstrate that when an EP coincides with a dissipative phase…

Quantum Physics · Physics 2026-04-14 Jongjun M. Lee

A numerical algorithm is proposed to explore in a systematic way the trajectories of the eigenvalues of non-Hermitian matrices in the parametric space and exploit this in order to find the locations of defective eigenvalues in the complex…

Computational Physics · Physics 2020-04-08 Benoit Nennig , Emmanuel Perrey-Debain

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