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Related papers: General theory for infernal points in non-Hermitia…

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We show that in a generic, ergodic quantum many-body system the interactions induce a non-trivial topology for an arbitrarily small non-hermitean component of the Hamiltonian. This is due to an exponential-in-system-size proliferation of…

Quantum Physics · Physics 2019-11-06 David J. Luitz , Francesco Piazza

A prominent feature of some one-dimensional non-Hermitian systems is that all right-eigenstates of the non-Hermitian Hamiltonian are localized in one end of the chain. The topological and trivial phases are distinguished by the emergence of…

Mesoscale and Nanoscale Physics · Physics 2019-07-17 Motohiko Ezawa

Non-Hermitian systems exhibit a distinctive phenomenon known as the non-Hermitian skin effect, where an extensive number of eigenstates become localized at the boundaries of a lattice with open boundaries. While the spectral winding number…

Materials Science · Physics 2025-04-17 Wuping Yang , H. Huang

The non-Hermitian skin effect and nonreciprocal behavior are sensitive to the boundary conditions, which are unique features of non-Hermitian systems. The eigenenergies will become complex and all eigenstates are localized at the boundary,…

Mesoscale and Nanoscale Physics · Physics 2024-07-15 Lei Chen , Zhen-Xia Niu , Xingran Xu

In a recent paper entitled "Winding around non-Hermitian singularities" by Zhong et al., published in Nat. Commun. 9, 4808 (2018), a formalism is proposed for calculating the permutations of eigenstates that arise upon encircling (multiple)…

Quantum Physics · Physics 2019-02-21 Eric J. Pap , Daniël Boer , Holger Waalkens

The non-Hermitian skin effect is fundamentally characterized by its sensitivity to boundary conditions, reflected in changes to the energy spectrum and boundary-localized eigenstates. Here, we demonstrate that a spatially inhomogeneous…

Mesoscale and Nanoscale Physics · Physics 2026-05-18 Zheng Wei , Ji-Yao Fan , Kui Cao , Xin-Ran Ma , Cui-Xian Guo , Xue-Ping Ren , Su-Peng Kou

We discuss the basic theoretical framework for non-Hermitian quantum systems with particular emphasis on the diagonalizability of non-Hermitian Hamiltonians and their $GL(1,\mathbb{C})$ gauge freedom, which are relevant to the adiabatic…

Quantum Physics · Physics 2019-04-03 Qi Zhang , Biao Wu

Non-Hermitian disordered systems have emerged as a central arena in modern physics, with ramifications spanning condensed matter, quantum, statistical, and high energy contexts. The same principles also underlie phenomena beyond physics,…

Mesoscale and Nanoscale Physics · Physics 2026-03-24 Kohei Kawabata , Shinsei Ryu

Non-Hermitian singularities are ubiquitous in non-conservative open systems. These singularities are often points of measure zero in the eigenspectrum of the system which make them difficult to access without careful engineering. Despite…

Quantum Physics · Physics 2018-05-24 Qi Zhong , Mercedeh Khajavikhan , Demetrios Christodoulides , Ramy El-Ganainy

The onset of thermalization in a closed finite system of randomly interacting bosons, at the level of a single eigenstate, is discussed. The main interest is in the emergence of the Bose-Einstein distribution of single-particle occupation…

Quantum Physics · Physics 2017-05-02 Fausto Borgonovi , Francesco Mattiotti , Felix M. Izrailev

Exceptional points (EPs) are special parameter values of a non-Hermitian eigenvalue problem where eigenfunctions corresponding to a multiple eigenvalue coalesce. In optics, EPs are associated with a number of counter-intuitive wave…

Optics · Physics 2019-10-08 Amgad Abdrabou , Ya Yan Lu

We study a non-Hermitian extension of the Creutz ladder with generic non-reciprocal hopping. By mapping the ladder onto two decoupled non-Hermitian Su--Schrieffer--Heeger (SSH) chains, we uncover a rich structure in parameter space under…

Quantum Physics · Physics 2025-12-24 Debashish Dutta , Sayan Choudhury

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

One of unique features of non-Hermitian systems is the extreme sensitive to their boundary conditions, e.g., the emergence of non-Hermitian skin effect (NHSE) under the open boundary conditions, where most of bulk states become localized at…

Disordered Systems and Neural Networks · Physics 2025-01-16 Hao Wang , Jin Liu , Tao Liu , Wen-Bo Ju

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

Open quantum and wave systems exhibit exotic degeneracies at exceptional points in parameter space that have attracted considerable attention in various fields of physics, including optics and photonics. One reason is the strong response of…

Quantum Physics · Physics 2022-05-18 Jan Wiersig

The high sensitivity of the spectrum and wavefunctions to boundary conditions, termed the non-Hermitian skin effect, represents a fundamental aspect of non-Hermitian systems. While it endows non-Hermitian systems with unprecedented physical…

Mesoscale and Nanoscale Physics · Physics 2025-01-30 Nan Cheng , Chang Shu , Kai Zhang , Xiaoming Mao , Kai Sun

Exceptional points (EPs) are central to non-Hermitian physics because of their unique properties and broad application prospects. While extensively studied in parity-time ($\mathcal{P}\mathcal{T}$)-symmetric systems and under Markovian…

Optics · Physics 2026-01-15 H. Z. Shen , X. C. Zhang , L. Y. Ning , Zhi-Guang Lu , Yan-Hui Zhou , Cheng Shang

Recent years have seen a growing interest in topological phases beyond the standard paradigm of gapped, isolated systems. One recent direction is to explore topological features in non-hermitian systems that are commonly used as effective…

Mesoscale and Nanoscale Physics · Physics 2026-02-03 Carlos Ortega-Taberner , Maria Hermanns

Quantum systems are often classified into Hermitian and non-Hermitian ones. Extraordinary non-Hermitian phenomena, ranging from the non-Hermitian skin effect to the supersensitivity to boundary conditions, have been widely explored. Whereas…

Quantum Gases · Physics 2022-05-25 Chenwei Lv , Ren Zhang , Zhengzheng Zhai , Qi Zhou