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Related papers: Non-Hermitian impurity problem

200 papers

We study the quantum localization phenomena of noninteracting particles in one-dimensional lattices based on tight-binding models with various forms of hopping terms beyond the nearest neighbor, which are generalizations of the famous…

Disordered Systems and Neural Networks · Physics 2011-02-16 J. Biddle , D. J. Priour , B. Wang , S. Das Sarma

A fundamental tenet of quantum mechanics is that the energy spectrum of a quantum system shall remain stable against infinitesimally weak and spatially confined perturbations. In this article, we demonstrate that this principle of spectral…

Mesoscale and Nanoscale Physics · Physics 2024-09-23 Chang Shu , Kai Zhang , Kai Sun

In contrast to Hermitian systems, eigenstates of non-Hermitian ones are in general nonorthogonal. This feature is most pronounced at exceptional points where several eigenstates are linearly dependent. In this work we show that near this…

Quantum Physics · Physics 2016-12-23 Alexander A. Zyablovsky , Evgeny S. Andrianov , Alexander A. Pukhov

Non-Hermiticity can destroy Anderson localization and lead to delocalization even in one dimension. However, the unified understanding of the non-Hermitian delocalization has yet to be established. Here, we develop a scaling theory of…

Disordered Systems and Neural Networks · Physics 2021-04-26 Kohei Kawabata , Shinsei Ryu

Non-Hermitian lattices can host the non-Hermitian skin effect, a boundary-induced collapse of all bulk eigenstates into exponentially localized edge modes. This effect underlies anomalous bulk-boundary correspondence and remarkable…

Optics · Physics 2026-05-19 Rohith Srikanth , Sashank Kaushik Sridhar , Avik Dutt

Particle transport and localization phenomena in condensed-matter systems can be modeled using a tight-binding lattice Hamiltonian. The ideal experimental emulation of such a model utilizes simultaneous, high-fidelity control and readout of…

Non-Hermitian topological matter provides a platform for engineering phenomena that go beyond the capabilities of Hermitian systems, enabling the use of losses to engineer topological phenomena. Non-Hermitian models often rely on artificial…

Wave localization is a fundamental phenomenon that appears universally in both natural materials and artificial structures and plays a crucial role in understanding the various physical properties of a system. Usually, a localized state has…

Mesoscale and Nanoscale Physics · Physics 2024-07-09 Xinrong Xie , Gan Liang , Fei Ma , Yulin Du , Yiwei Peng , Erping Li , Hongsheng Chen , Linhu Li , Fei Gao , Haoran Xue

The bulk states of Hermitian systems are believed insensitive to local Hermitian impurities or perturbations except for a few impurity-induced bound states. Thus, it is important to ask whether \textit{local} non-Hermiticity can cause…

Quantum Physics · Physics 2023-05-02 Cui-Xian Guo , Xueliang Wang , Haiping Hu , Shu Chen

We present a brief review of physical problems leading to indefinite Hilbert spaces and non-hermitian Hamiltonians. With the exception of pseudo-Riemannian manifolds in GR, the problem of a consistent physical interpretation of these…

Quantum Physics · Physics 2016-09-08 A. Ramirez , B. Mielnik

Boundary conditions can have dramatic impact in non-Hermitian systems, as exemplified by the non-Hermitian skin effect. Focusing on one-dimensional non-Hermitian quasiperioidic lattices, we show that the interplay of quasiperiodicity and…

Quantum Physics · Physics 2026-03-24 Wenzhi Wang , Tianyu Li , Wei Yi

We predict and analyze boundary-driven exceptional points in semi-infinite Hermitian photonic waveguide lattices with a side-coupled defect. The exceptional points arise from coherent reflections at the lattice termination, which induce…

Optics · Physics 2026-03-10 Stefano Longhi

We study a non-interacting quantum particle, moving on a one-dimensional lattice, which is subjected to repetitive measurements. We investigate the consequence when such motion is interrupted and restarted from the same initial…

Quantum Physics · Physics 2023-03-21 Ranjan Modak , S. Aravinda

We study Anderson localization in disordered tight-binding models on hyperbolic lattices. Such lattices are geometries intermediate between ordinary two-dimensional crystalline lattices, which localize at infinitesimal disorder, and Bethe…

Disordered Systems and Neural Networks · Physics 2024-08-20 Anffany Chen , Joseph Maciejko , Igor Boettcher

I show that a single embedded non-Hermitian defect in a one-dimensional topological system at certain degrees of non-Hermiticity can remove the topological mode from the edge and restore it inside the lattice at the same place where the…

Quantum Physics · Physics 2022-07-26 Hamidreza Ramezani

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

Exceptional points (EPs) are non-Hermitian singularities associated with the coalescence of individual eigenvectors accompanied by the degeneracy of their complex energies. Here, we report the discovery of a generalization to the concept of…

Quantum Physics · Physics 2026-05-07 Zhen Li , Xulong Wang , Rundong Cai , Kenji Shimomura , Congwei Lu , Zhesen Yang , Masatoshi Sato , Guancong Ma

We study the localization properties of a disordered tight-binding Hamiltonian on a generic bipartite lattice close to the band center. By means of a fermionic replica trick method, we derive the effective non-linear $\sigma$-model…

Disordered Systems and Neural Networks · Physics 2009-10-31 Michele Fabrizio , Claudio Castellani

Disorder and non-Hermiticity dramatically impact the topological and localization properties of a quantum system, giving rise to intriguing quantum states of matter. The rich interplay of disorder, non-Hermiticity, and topology is…

Mesoscale and Nanoscale Physics · Physics 2022-06-15 Quan Lin , Tianyu Li , Lei Xiao , Kunkun Wang , Wei Yi , Peng Xue

Analytical complexity of quantum wavefunction whose argument is extended into the complex plane provides an important information about the potentiality of manifesting complex quantum dynamics such as time-irreversibility, dissipation and…

Statistical Mechanics · Physics 2015-06-17 Hiroaki S. Yamada , Kensuke S. Ikeda