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Related papers: Quantifying non-Hermiticity using single- and many…

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The interaction picture in a non-Hermitian realization is discussed in detail and considered for its practical use in many-body quantum physics. The resulting non-Hermitian interaction-picture (NHIP) description of dynamics, in which both…

Quantum Physics · Physics 2020-04-29 R. F. Bishop , M. Znojil

We construct uncertainty relation for arbitrary finite dimensional PT invariant non-Hermitian quantum systems within a special inner product framework. This construction is led by good observables which are a more general class of…

Quantum Physics · Physics 2023-04-11 Namrata Shukla , Ranjan Modak , Bhabani Prasad Mandal

Hamiltonian Mechanics works for conserved systems and Quantum Mechanics is given in Hamiltonian language. It is considered that complexifying the quantum Hamiltonian, a balanced loss and gain model can be created. The usual mathematics of…

General Physics · Physics 2015-12-03 Chetan Waghela

Parity-time ($PT$) symmetric Hamiltonians are generally non-Hermitian and give rise to exotic behaviour in quantum systems at exceptional points, where eigenvectors coalesce. The recent realisation of $PT$-symmetric Hamiltonians in quantum…

In several situations, most notably when describing metastable states, a system can evolve according to an effective non hermitian Hamiltonian. To each eigenvalue of a non hermitian Hamiltonian is associated an eigenstate $\vert\phi\rangle$…

Quantum Physics · Physics 2009-10-30 Y. Aharonov , S. Massar , S. Popescu , J. Tollaksen , L. Vaidman

We propose random non-Hermitian Hamiltonians to model the generic stochastic nonlinear dynamics of a quantum state in Hilbert space. Our approach features an underlying linearity in the dynamical equations, ensuring the applicability of…

Quantum Physics · Physics 2025-07-31 Pei Wang

In recent years, non-Hermitian phases in classical and quantum systems have garnered significant attention. In particular, their intriguing band geometry offers a platform for exploring unique topological states and unconventional quantum…

Mesoscale and Nanoscale Physics · Physics 2023-10-10 Ayan Banerjee , Arka Bandyopadhyay , Ronika Sarkar , Awadhesh Narayan

Manifestly non-Hermitian quantum graphs with real spectra are introduced and shown tractable as a new class of phenomenological models with several appealing descriptive properties. For illustrative purposes, just equilateral star-graphs…

High Energy Physics - Theory · Physics 2009-11-10 Miloslav Znojil

A minimum length scale of the order of Planck length is a feature of many models of quantum gravity that seek to unify quantum mechanics and gravitation. Recently, Perivolaropoulos in his seminal work [Phys. Rev.D 95, 103523 (2017)]…

High Energy Physics - Theory · Physics 2021-12-23 Latévi M. Lawson

We study inter-chain pair tunnelling dynamics based on an exact two-particle solution for a two-leg ladder. We show that the Hermitian Hamiltonian shares a common two-particle eigenstate with a corresponding non-Hermitian Hubbard…

Strongly Correlated Electrons · Physics 2017-05-29 X. Z. Zhang , L. Jin , Z. Song

The geometry of Hamiltonian's eigenstates is encoded in the quantum geometric tensor (QGT). It contains both the Berry curvature, central to the description of topological matter and the quantum metric. So far the full QGT has been measured…

Mesoscale and Nanoscale Physics · Physics 2021-09-08 Qing Liao , Charly Leblanc , Jiahuan Ren , Feng Li , Yiming Li , Dmitry Solnyshkov , Guillaume Malpuech , Jiannian Yao , Hongbing Fu

A review is given on the foundations and applications of non-Hermitian classical and quantum physics. First, key theorems and central concepts in non-Hermitian linear algebra, including Jordan normal form, biorthogonality, exceptional…

Mesoscale and Nanoscale Physics · Physics 2021-04-28 Yuto Ashida , Zongping Gong , Masahito Ueda

The requirement of Hermiticity of a Quantum Mechanical Hamiltonian, for the description of physical processes with real eigenvalues which has been challenged notably by Carl Bender, is examined for the case of a Fock space Hamilitonian…

High Energy Physics - Theory · Physics 2009-11-10 David B. Fairlie , Jean Nuyts

The quantum measurement axiom dictates that physical observables and in particular the Hamiltonian must be diagonalizable and have a real spectrum. For a time-independent Hamiltonian (with a discrete spectrum) these conditions ensure the…

Quantum Physics · Physics 2009-11-13 Ali Mostafazadeh

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

We explain why the main conclusion of Bender et al, hep-th/0511229 [J. Phys. A 39 (2006) 1657] regarding the practical superiority of the non-Hermitian description of PT-symmetric quantum systems over their Hermitian description is not…

High Energy Physics - Theory · Physics 2007-05-23 Ali Mostafazadeh

The phenomenon of degeneracy of an $N-$plet of bound states is studied in the framework of quantum theory of closed (i.e., unitary) systems. For an underlying Hamiltonian $H=H(\lambda)$ the degeneracy occurs at a Kato's exceptional point…

Quantum Physics · Physics 2020-10-29 Miloslav Znojil

We review the methodology to theoretically treat parity-time- ($\mathcal{PT}$-) symmetric, non-Hermitian quantum many-body systems... (For the full abstract see paper)

Quantum Physics · Physics 2023-11-17 Volker Meden , Lukas Grunwald , Dante M. Kennes

Non-Hermitian quantum many-body systems feature steady-state entanglement transitions driven by the competition between unitary dynamics and dissipation. In this work, we reveal the fundamental role of conservation laws in shaping this…

Statistical Mechanics · Physics 2025-10-14 Rafael D. Soares , Youenn Le Gal , Chun Y. Leung , Dganit Meidan , Alessandro Romito , Marco Schirò

Extended quantum mechanics using non-Hermitian, pseudo-Hermitian Hamiltonians is briefly reviewed. Supersymmetric regularizations, solvable simulations and large-N expansion techniques are recollected as suitable means for the study of…

Quantum Physics · Physics 2009-11-10 Miloslav Znojil