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Related papers: Non-Hermitian systems with a real spectrum and sel…

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Certain non-Hermitian systems exhibit the skin effect, whereby the wavefunctions become exponentially localized at one edge of the system. Such exponential amplification of wavefunction has received significant attention due to its…

Quantum Physics · Physics 2024-03-26 Haowei Xu , Uroš Delić , Guoqing Wang , Changhao Li , Paola Cappellaro , Ju Li

Non-Hermiticity gives rise to unique topological phases without Hermitian analogs. However, the effective field theory has yet to be established. Here, we develop a field-theoretical description of the intrinsic non-Hermitian topological…

Mesoscale and Nanoscale Physics · Physics 2021-06-01 Kohei Kawabata , Ken Shiozaki , Shinsei Ryu

We show that two-dimensional non-Hermitian photonic crystals made of lossy material can exhibit non-trivial point gap topology in terms of topological winding in its complex frequency band structure. Such crystals can be either made of…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 Janet Zhong , Kai Wang , Yubin Park , Viktar Asadchy , Charles C. Wojcik , Avik Dutt , Shanhui Fan

The non-Hermitian model exhibits counterintuitive phenomena that are not observed in the Hermitian counterparts. To probe the competition between non-Hermitian and Hermitian interacting components of the Hamiltonian, we focus on a system…

We analyse a class of non-Hermitian Hamiltonians, which can be expressed bilinearly in terms of generators of a sl(2,R)-Lie algebra or their isomorphic su(1,1)-counterparts. The Hamlitonians are prototypes for solvable models of Lie…

Quantum Physics · Physics 2008-11-21 Paulo E. G. Assis , Andreas Fring

Non-Hermitian systems exhibit nontrivial band topology and a strong sensitivity of the energy spectrum on the boundary conditions. Remarkably, a macroscopic number of bulk states get squeezed toward the lattice edges under open boundary…

Quantum Physics · Physics 2022-07-26 Stefano Longhi

This work uncovers a new class of criticality where eigenenergies and eigenstates of non-Hermitian lattice systems jump discontinuously across a critical point in the thermodynamic limit, unlike established Hermitian and non-Hermitian…

Mesoscale and Nanoscale Physics · Physics 2020-11-03 Linhu Li , Ching Hua Lee , Sen Mu , Jiangbin Gong

Systems with non-Hermitian skin effects are very sensitive to the imposed boundary conditions and lattice size, and thus an important question is whether non-Hermitian skin effects can survive when deviating from the open boundary…

Quantum Physics · Physics 2021-09-15 Cui-Xian Guo , Chun-Hui Liu , Xiao-Ming Zhao , Yanxia Liu , Shu Chen

A possible method to investigate non-Hermitian Hamiltonians is suggested through finding a Hermitian operator $\eta_+$ and defining the annihilation and creation operators to be $\eta_+$-pseudo-Hermitian adjoint to each other. The operator…

Quantum Physics · Physics 2014-06-06 Jun-Qing Li , Yan-Gang Miao , Zhao Xue

Non-Hermitian lattices under semi-infinite boundary conditions sustain an extensive number of exponentially-localized states, dubbed non-Hermitian skin modes. Such states can be predicted from the nontrivial topology of the energy spectrum…

Quantum Physics · Physics 2022-07-26 Stefano Longhi

In the last two decades, the ubiquitous effect of dissipation has proven to entail astonishing non-Hermitian features, rather than just being an inescapable nuisance. As an alternative route to non-Hermiticity, we tailor the anisotropy of a…

In this paper, we present a concrete example that highlights how predictions in non-Hermitian quantum mechanics can be inaccurately influenced by the absence of environment-induced fluctuations in the model. Specifically, we investigate the…

Quantum Physics · Physics 2024-08-27 Clement Ehrhardt , Jonas Larson

The non-Hermitian skin effect (NHSE), characterized by extensive boundary accumulation of eigenstates under open boundary conditions, has emerged as a central phenomenon in non-Hermitian physics. Conventionally, the NHSE arises from either…

A non-unitary transformation leading to a Hatano-Nelson problem is performed on an array of equally-spaced optical waveguides. Such transformation produces a non-reciprocal system of waveguides, as the corresponding Hamiltonian becomes…

Optics · Physics 2023-07-17 Ivan Bocanegra , Héctor M. Moya-Cessa

Non-Hermitian physics has received great attention recently. In particular, band structures in non-Hermitian systems can be engineered to exhibit various topological effects. Among them, one of the most intriguing phenomena is the…

Quantum Physics · Physics 2024-04-24 Wenwen Liu , Oubo You , Bumki Min , Shuang Zhang

There are various research strategies used for non-Hermitian systems, which typically involve introducing non-Hermitian terms to pre-existing Hermitian Hamiltonians. It can be challenging to directly design non-Hermitian many-body models…

Quantum Physics · Physics 2023-06-02 Ruohan Shen , Yuchen Guo , Shuo Yang

The excitation properties of quantum many-body systems are encoded in their response functions. These functions define an associated response Hamiltonian, which is intrinsically non-Hermitian due to the dissipative nature of retarded…

Mesoscale and Nanoscale Physics · Physics 2025-09-24 Zhesen Yang , Zihan Wang , Juntao Huang , Zijian Zheng , Jiangping Hu

We generalize a recently proposed approach for the construction of pseudo-Hermitian Hamiltonians with real spectra. Present technique is based on a simple and straightforward similarity transformation of the coordinate and momentum.

Quantum Physics · Physics 2016-04-21 Francisco M. Fernández

We show that degenerate four-wave mixing (FWM) in nonlinear optics can be described by an effective Hamiltonian that is pseudo-Hermitian, which enables a transition between a pseudo-Hermitian phase with real eigenvalues and a broken…

Optics · Physics 2016-03-18 Li Ge , Wenjie Wan

Nonreciprocal nonhermitian systems provide an unconventional localization mechanism of topological zero modes via the nonhermitian skin effect. While fundamental theoretical characterizations of this effect involve the biorthogonal system…

Mesoscale and Nanoscale Physics · Physics 2020-01-22 Henning Schomerus