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Related papers: Complexity from the Reduced Density Matrix: a new …

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Through semiclassical methods the subject of quantum chaos motivates and depends on Hamiltonian chaos research. Presented here is a selection of Hamiltonian chaos topics that in this way get directly related to any of a variety of quantum…

Quantum Physics · Physics 2026-04-15 Steven Tomsovic

We investigate the spread complexity of a generic two-level subsystem of a larger system to analyze the influence of energy level statistics, comparing chaotic and integrable systems. Initially focusing on the nearest-neighbor level…

High Energy Physics - Theory · Physics 2025-04-28 Amin Faraji Astaneh , Niloofar Vardian

Complex quantum systems -- composed of many, interacting particles -- are intrinsically difficult to model. When a quantum many-body system is subject to disorder, it can undergo transitions to regimes with varying non-ergodic and localized…

The relationship between chaos and quantum mechanics has been somewhat uneasy -- even stormy, in the minds of some people. However, much of the confusion may stem from inappropriate comparisons using formal analyses. In contrast, our…

We apply a recently developed measure of multiscale complexity to the Gaussian model consisting of continuous spins with bilinear interactions for a variety of interaction matrix structures. We find two universal behaviors of the complexity…

Statistical Mechanics · Physics 2009-11-10 Richard Metzler , Yaneer Bar-Yam

We demonstrate the presence of chaos in stochastic simulations that are widely used to study biodiversity in nature. The investigation deals with a set of three distinct species that evolve according to the standard rules of mobility,…

Biological Physics · Physics 2017-03-28 D. Bazeia , M. B. P. N. Pereira , A. V. Brito , B. F. de Oliveira , J. G. G. S. Ramos

The detection and estimation of quantum entanglement are the essential issues in the theory of quantum entanglement. We construct matrices based on the realignment of density matrices and the vectorization of the reduced density matrices,…

Quantum Physics · Physics 2024-05-21 Jiaxin Sun , Hongmei Yao , Shao-Ming Fei , Zhaobing Fan

We study the behavior of an open quantum system, with an $N$--dimensional space of states, whose density matrix evolves according to a non--unitary map defined in two steps: A unitary step, where the system evolves with an evolution…

Quantum Physics · Physics 2009-11-07 Pablo Bianucci , Juan Pablo Paz , Marcos Saraceno

This paper formulates a new approach to the study of chaos in discrete dynamical systems based on the notions of inverse ill-posed problems, set-valued mappings, generalized and multivalued inverses, graphical convergence of a net of…

Chaotic Dynamics · Physics 2007-05-23 A. Sengupta

The stability of quantum systems to perturbations of the Hamiltonian is studied. This stability is quantified by the fidelity. Dependence of fidelity on the initial state as well as on the dynamical properties of the system is considered.…

Quantum Physics · Physics 2007-05-23 Marko Znidaric

For chaotic quantum dynamics modeled by random unitary circuits, we study the complexity of reduced density matrices of subsystems as a function of evolution time where the initial global state is a product pure state. The state complexity…

Quantum Physics · Physics 2026-04-30 Jeongwan Haah , Douglas Stanford

We propose a phase-space Wigner harmonics entropy measure for many-body quantum dynamical complexity. This measure, which reduces to the well known measure of complexity in classical systems and which is valid for both pure and mixed states…

Quantum Physics · Physics 2010-10-22 Vinitha Balachandran , Giuliano Benenti , Giulio Casati , Jiangbin Gong

Nowadays there is no universally accepted definition of quantum chaos. In this paper we review and critically discuss different approaches to the subject, such as Quantum Chaology and the Random Matrix Theory. Then we analyze the problem of…

chao-dyn · Physics 2009-10-31 V. R. Manfredi , L. Salasnich

Until now, most memristor-based chaotic circuits proposed in the literature are based on mathematical models which assume ideal characteristics such as piece-wise linear or cubic non-linearities. The idea, illustrated here and originating…

Chaotic Dynamics · Physics 2015-09-02 L. V. Gambuzza , L. Fortuna , M. Frasca , E. Gale

Quantifying the complexity of quantum states is a longstanding key problem in various subfields of science, ranging from quantum computing to the black-hole theory. The lower bound on quantum pure state complexity has been shown to grow…

Quantum Physics · Physics 2025-05-22 Yusen Wu , Bujiao Wu , Yanqi Song , Xiao Yuan , Jingbo B. Wang

We present a unified framework for the quantization of a family of discrete dynamical systems of varying degrees of "chaoticity". The systems to be quantized are piecewise affine maps on the two-torus, viewed as phase space, and include the…

High Energy Physics - Theory · Physics 2009-10-28 S. De Bievre , M. Degli Esposti , R. Giachetti

We experimentally report on the detection of chaos from a free-running commercial broad-area VCSEL without the need for external perturbation such as optical feedback, injection or current modulation. The evolution of nonlinear dynamics…

Optics · Physics 2025-01-28 Jules Mercadier , Stefan Bittner , Damien Rontani , Marc Sciamanna

The quantum phase diagram for a finite $3$-level system in the $\Lambda$ configuration, interacting with a two-mode electromagnetic field in a cavity, is determined by means of information measures such as fidelity, fidelity susceptibility…

Quantum Physics · Physics 2023-02-21 O. Castaños , S. Cordero , R. López-Peña , E. Nahmad-Achar

We study the phase space of periodically modulated gravitational cavity by means of quantum recurrence phenomena. We report that the quantum recurrences serve as a tool to connect phase space of the driven system with spectrum in quantum…

Quantum Physics · Physics 2009-11-06 Farhan Saif

It is straightforward to calculate the conductance of a quantum device once all its scattering centers are fully specified. However, to do this in reverse, i.e., to find information about the composition of scatterers in a device from its…

Mesoscale and Nanoscale Physics · Physics 2022-02-25 S. Mukim , F. P. Amorim , A. R. Rocha , R. B. Muniz , C. Lewenkopf , M. S. Ferreira