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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

Recent years have seen remarkable development in open quantum systems effectively described by non-Hermitian Hamiltonians. A unique feature of non-Hermitian topological systems is the skin effect, anomalous localization of an extensive…

Statistical Mechanics · Physics 2023-04-14 Kohei Kawabata , Tokiro Numasawa , Shinsei Ryu

Parity-time (PT)-symmetric Hamiltonians have widespread significance in non-Hermitian physics. A PT-symmetric Hamiltonian can exhibit distinct phases with either real or complex eigenspectrum, while the transition points in between, the…

Quantum Physics · Physics 2021-07-13 Lei Xiao , Tianshu Deng , Kunkun Wang , Zhong Wang , Wei Yi , Peng Xue

We analyze the scattering dynamics and spectrum of a quantum particle on a tight-binding lattice subject to a non-Hermitian (purely imaginary) local potential. The reflection, transmission and absorption coefficients are studied as a…

Quantum Physics · Physics 2020-07-20 Phillip C. Burke , Jan Wiersig , Masudul Haque

Hermitian theories play a major role in understanding the physics of most phenomena. It has been found only in the past decade that non-Hermiticity enables unprecedented effects such as exceptional points, spectral singularities and bulk…

Applied Physics · Physics 2021-10-04 Xiujuan Zhang , Yuan Tian , Jian-Hua Jiang , Ming-Hui Lu , Yan-Feng Chen

The Dicke model, which describes the collective interaction between an ensemble of atoms and a single-mode photon field, serves as a fundamental framework for studying light-matter interactions and quantum electrodynamic phenomena. In this…

Quantum Physics · Physics 2024-11-14 Bin Jiang , Yi-Yang Li , Junjie Liu , Chen Wang , Jian-Hua Jiang

We discuss the short-time perturbative expansion of the linear entropy for finite-dimensional quantum systems whose dynamics can be effectively described by a non-Hermitian Hamiltonian. We derive a timescale for the degree of mixedness for…

Quantum Physics · Physics 2023-02-07 Diego Paiva Pires , Tommaso Macrì

The metrological limits of thermometry operated in nonequilibrium dynamical regimes are analyzed. We consider a finite-dimensional quantum system, employed as a quantum thermometer, in contact with a thermal bath inducing Markovian…

Non-Hermitian physics has unlocked a wealth of unconventional wave phenomena beyond the reach of Hermitian systems, with exceptional points (EPs) driving enhanced sensitivity, nonreciprocal transport, and topological behavior unique to…

One of the important features of non-Hermitian Hamiltonians is the existence of a unique type of singularities, the so-called exceptional points (EPs). When the corresponding systems operate around such singularities, they exhibit…

Optics · Physics 2025-08-26 Ioannis Kiorpelidis , Konstantinos G. Makris

Quantum sensing exploits fundamental features of quantum system to achieve highly efficient measurement of physical quantities. Here, we propose a strategy to realize a single-qubit pseudo-Hermitian sensor from a dilated two-qubit Hermitian…

Quantum Physics · Physics 2020-01-22 Yaoming Chu , Yu Liu , Haibin Liu , Jianming Cai

We investigate a non-Hermitian model featuring non-reciprocal gradient hoppings. Through an in-depth analysis of the Liouvillian spectrum and dynamics, we confirm the emergence of the Liouvillian skin effect resulting from the…

Quantum Physics · Physics 2023-09-21 Zeqing Wang , Yao Lu , Yi Peng , Ran Qi , Yucheng Wang , Jianwen Jie

From biological ecosystems to spin glasses, connectivity plays a crucial role in determining the function, dynamics, and resiliency of a network. In the realm of non-Hermitian physics, the possibility of complex and asymmetric exchange…

For non-Hermitian quantum models, the dynamics is apparently not reflected by the static properties, e.g., the complex energy spectrum, because of the nonorthogonality of the right eigenvectors, the nonunitarity of the time evolution, the…

Quantum Physics · Physics 2021-01-12 Li-Jun Lang , Yijiao Weng , Yunhui Zhang , Enhong Cheng , Qixia Liang

The non-Hermitian skin effect (NHSE) is a distinctive topological phenomenon observed in nonHermitian systems. Recently, there has been considerable interest in exploring higher-order NHSE occurrences in two and three dimensions. In such…

Non-Hermitian Hamiltonians provide an alternative perspective on the dynamics of quantum and classical systems coupled non-conservatively to an environment. Once primarily an interest of mathematical physicists, the theory of non-Hermitian…

Mesoscale and Nanoscale Physics · Physics 2022-12-20 Hilary M. Hurst , Benedetta Flebus

We revisit the fate of the skin modes in many-body non-Hermitian fermionic systems. Contrary to the single-particle case, the many-body ground state cannot exhibit an exponential localization of all eigenstates due to the Pauli exclusion…

Mesoscale and Nanoscale Physics · Physics 2023-05-05 Faisal Alsallom , Loïc Herviou , Oleg V. Yazyev , Marta Brzezińska

We numerically study topological effects of electromagnetic (EM) waves in a two-dimensional (2D) non-Hermitian photonic crystal (PhC) composed of lossy magneto-optical materials. In this system, not only the EM wavefunctions but also the…

Optics · Physics 2026-04-28 Huyen Thanh Phan , Katsunori Wakabayashi

Non-Hermitian models with real eigenenergies are highly desirable for their stability. Yet, most of the currently known ones are constrained by symmetries such as PT-symmetry, which is incompatible with realizing some of the most exotic…

Mesoscale and Nanoscale Physics · Physics 2022-07-13 Boxue Zhang , Qingya Li , Xiao Zhang , Ching Hua Lee

Critical states in quasiperiodic systems defy the conventional dichotomy between extended and localized states. In this work, we demonstrate that non-Hermiticity fundamentally reshapes this paradigm by giving rise to an exactly solvable…

Mesoscale and Nanoscale Physics · Physics 2026-02-02 Zhangyuan Chen , Muhammad Idrees , Ying Yang , Xianqi Tong , Xiaosen Yang