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We study the quantum phase transition (QPT) in a non-Hermitian Tavis-Cummings (TC) model of experimentally accessible parameters, which is engineered with two drive fields applied to an ensemble of two-level systems (TLSs) and a cavity,…

Quantum Physics · Physics 2020-09-15 Guo-Qiang Zhang , Zhen Chen , J. Q. You

We illustrate that a Hermitian nonlinear optical system consisting of hybridized parametric amplification and second harmonic generation mimics non-Hermitian evolution dynamics. Oscillation damping, evolution to a static steady state, and…

Optics · Physics 2021-01-05 Noah Flemens , Nicolas Swenson , Jeffrey Moses

In this paper, we develop spectral analysis of a discrete non-Hermitian quantum system that is a discrete counterpart of some continuous quantum systems on a complex contour. In particular, simple conditions for discreteness of the spectrum…

Mathematical Physics · Physics 2009-01-20 Ebru Ergun

We present a theoretical framework for a $\mathcal{PT}$-symmetric double-cavity molecular optomechanical system demonstrating nonreciprocal enhancement of multipartite quantum entanglement at elevated temperatures. All bipartite…

Quantum Physics · Physics 2026-01-01 E. Kongkui Berinyuy , C. Tchodimou , P. Djorwé , S. K. Singh , S. G. Nana Engo

Decoherence and dissipation, arising from unavoidable interactions with the environment, can exert a dual influence on transport in physical systems, suppressing coherent propagation while inducing diffusion and mitigating localization in…

Quantum Physics · Physics 2026-04-15 Kunkun Wang , Lei Xiao , Stefano Longhi , Peng Xue

We examine the conditions in favor and necessity of a realistic multileveled description of a decohering quantum system. Under these conditions approximate techniques to simplify a multileveled system by its first two levels is unreliable…

Quantum Physics · Physics 2007-05-23 Kerim Savran , Tugrul Hakioglu , Emine Mese

Recently, the study of non-Hermitian physics has attracted considerable attention. The modified bulk-boundary correspondence has been proposed to understand topological edge states in non-Hermitian static systems. Here we report a new…

Optics · Physics 2019-06-18 Bo Wang , Tian Chen , Xiangdong Zhang

Coherent control of self-contained quantum systems offers the possibility to fabricate smallest thermal transistors. The steady coherence created by the delocalization of electronic excited states arouses nonlinear heat transports in…

Quantum Physics · Physics 2018-11-07 Shanhe Su , Yanchao Zhang , Bjarne Andresen , Jincan Chen

The supersymmetric structure of a generalized non-Hermitian driven two-level system is demonstrated. A unitary rotation turns the Hamiltonian into a more convenient form. After decoupling a set of differential equations, the supersymmetric…

Quantum Physics · Physics 2025-10-16 Ivan A. Bocanegra-Garay , Luis M. Nieto

Non-Hermitian systems have attracted considerable interest in recent years owing to their unique topological properties that are absent in Hermitian systems. While such properties have been thoroughly characterized in free fermion models,…

Quantum Physics · Physics 2023-09-14 Yuchen Guo , Ruohan Shen , Shuo Yang

In an externally driven multilevel quantum system observation that the NEXT jump has not yet happened affects its future development. In previous work [Phys. Rev. A36, 929 (1987)] it was shown that this class of measurement makes it…

Quantum Physics · Physics 2022-08-24 Massimo Porrati , Nicholas Penthorn , John Rooney , Hong Wen Jiang , Seth Putterman

Quantum collision models normally consist of a system interacting with a set of ancillary units representing the environment. While these ancillary systems are usually assumed to be either two level systems (TLS) or harmonic oscillators, in…

Quantum Physics · Physics 2024-05-31 Stefano Cusumano , Gabriele De Chiara

In this paper, we extend the result of [Andreas Fring et al J. Phys. A 43, 345401 (2010)] in noncommutative phase-space (NCPS). We compute the non-Hermitian Hamiltonian of a harmonic oscillator in NCPS. We construct a new P T-symmetry in…

Quantum Physics · Physics 2023-09-28 Emanonfi Elias N'Dolo

Canonical quantum mechanics postulates Hermitian Hamiltonians to ensure real eigenvalues. Counterintuitively, a non-Hermitian Hamiltonian, satisfying combined parity-time (PT) symmetry, could display entirely real spectra above some…

Optics · Physics 2025-01-23 Jianming Wen , Xiaoshun Jiang , Liang Jiang , Min Xiao

We reveal several distinct regimes of the relaxation dynamics of a small quantum system coupled to an environment within the plane of the dissipation strength and the reservoir temperature. This is achieved by discriminating between…

Quantum Physics · Physics 2015-06-17 D. M. Kennes , O. Kashuba , V. Meden

Quantum coherence conservation is shown to be achieved by a very high rate of dissipation of an environmental system coupled with a principal system. This effect is not in the list of previously-known strategies of noise suppression, such…

Quantum Physics · Physics 2007-10-24 Akira SaiToh , Robabeh Rahimi , Mikio Nakahara

We compare approaches to evaluation of decoherence at low temperatures in two-state quantum systems weakly coupled to the environment. By analyzing an exactly solvable model, we demonstrate that a non-Markovian approximation scheme yields…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Dmitry Solenov , Vladimir Privman

In the context of traditional quantum-control considerations it is conjectured that one of the promising new strategies of the constructive model building could be sought in a non-stationary upgrade of the formalism of PT-symmetric quantum…

Quantum Physics · Physics 2015-07-14 Miloslav Znojil

Quantum information processing with multi-level systems (qudits) provides additional features and applications than the two-level systems. However, qudits are more prone to dephasing and dynamical decoupling for qudits has never been…

The congregation of topological quantum and classical systems with the ideas of non-Hermitian physics has generated enormous research interest in the last few years. While the concepts associated to non-trivial topological aspects have…

Applied Physics · Physics 2021-08-27 Nitish Kumar Gupta , Arun M. Jayannavar