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Quantum Darwinism builds on decoherence theory to explain the emergence of classical behavior in a fundamentally quantum universe. Within this framework we prove two crucial insights about the emergence of classical phenomenology, centered…

Quantum Physics · Physics 2024-10-16 Akram Touil , Fabio Anza , Sebastian Deffner , James P. Crutchfield

A general theoretical framework for decoherence is proposed, which encompasses formalisms originally devised to deal just with open or with closed systems. The conditions for decoherence are clearly stated and the relaxation and decoherence…

Quantum Physics · Physics 2009-10-30 Mario Castagnino , Sebastian Fortin , Roberto Laura , Olimpia Lombardi

We construct a quantum system of spherical spins with a continuous local symmetry. The model is exactly soluble in the thermodynamic limit and exhibits a number of interesting properties. We show that the local symmetry is spontaneously…

High Energy Physics - Theory · Physics 2015-02-18 Pedro R. S. Gomes , P. F. Bienzobaz

The functional method, introduced to deal with systems endowed with a continuous spectrum, is used to study the problem of decoherence and correlations in a simple cosmological model.

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mario Castagnino

Superstatistics is an elegant framework for the description of steady-state thermodynamics, mostly used for systems with long-range interactions such as plasmas. In this work, we show that the potential energy distribution of a classical…

Statistical Mechanics · Physics 2025-03-25 Sergio Davis , Claudia Loyola , Carlos Femenías , Joaquín Peralta

We introduce the idea of weakly coherent collisional models, where the elements of an environment interacting with a system of interest are prepared in states that are approximately thermal, but have an amount of coherence proportional to a…

Description of nonclassicality of states has hitherto been through violation of Bell inequality and non-separability, with the latter being a stronger constraint. In this paper, we show that this can be further sharpened, by introducing the…

Quantum Physics · Physics 2015-06-18 H. M. Bharath , V. Ravishankar

The problem of emergence of classicality from quantum mechanics has been addressed over time through numerous frameworks, from Bohr's correspondence principle to quantum Darwinism. Traditional approaches associate the emergence of…

Quantum Physics · Physics 2025-01-27 D. M. Fucci , L. F. Gaissler , R. M. Angelo

A classical system cannot escape out of a metastable state at zero temperature. However, a composite system made from both classical and quantum degrees of freedom may drag itself out of the metastable state by a sequential process. The…

Superconductivity · Physics 2009-06-25 A. U. Thomann , V. B. Geshkenbein , G. Blatter

The coherent states for a particle on a sphere are introduced. These states are labelled by points of the classical phase space, that is the position on the sphere and the angular momentum of a particle. As with the coherent states for a…

Quantum Physics · Physics 2008-11-26 K. Kowalski , J. Rembielinski

The roles of decoherence and environment-induced superselection in the emergence of the classical from the quantum substrate are described. The stability of correlations between the einselected quantum pointer states and the environment…

Quantum Physics · Physics 2011-08-04 Wojciech H. Zurek

We numerically investigate decoherence of a two-spin system (central system) by a bath of many spins 1/2. By carefully adjusting parameters, the dynamical regime of the bath has been varied from quantum chaos to regular, while all other…

Quantum Physics · Physics 2009-11-10 J. Lages , V. V. Dobrovitski , B. N. Harmon

We describe quantum and classical Hamiltonian dynamics in a common Hilbert space framework, that allows the treatment of mixed quantum-classical systems. The analysis of some examples illustrates the possibility of entanglement between…

Quantum Physics · Physics 2011-11-28 H. R. Jauslin , D. Sugny

We show that when the thermal wavelength is comparable to the spatial size of a system, thermodynamic observables like Pressure and Volume have quantum fluctuations that cannot be ignored. They are now represented by operators; conventional…

Statistical Mechanics · Physics 2008-07-30 Antonin Coutant , S. G. Rajeev

We discuss the transition from a quantum to a classical domain for a model where a separation into environment and system is explicitely not given. Utilizing the coarse graining procedure for free quantum fields we also apply the projection…

Quantum Physics · Physics 2007-05-23 A. M. Lisewski

We study two-dimensional classically integrable field theory with independent boundary condition on each end, and obtain three possible generating functions for integrals of motion when this model is an ultralocal one. Classically…

High Energy Physics - Theory · Physics 2008-11-26 Yi-Xin Chen , Xu-Dong Luo , Ke Wu

A thought experiment is discussed to clarify the concept of decoherence. Superposition of states consisting of ground state of a single hydrogen atom and its excited state after a huge amount of time is discussed to show that the…

Quantum Physics · Physics 2012-09-04 Shunichi Muto

The precision of nonequilibrium thermodynamic systems is fundamentally limited, yet how quantum coherence shapes these limits remains largely unexplored. A general theoretical framework is introduced that explicitly links quantum coherence…

Quantum Physics · Physics 2025-10-27 Shanhe Su , Cong Fu , Ousi Pan , Shihao Xia , Fei Liu , Jincan Chen

We study numerically the damping of quantum oscillations and the increase of entropy with time in model spin systems decohered by a spin bath. In some experimentally relevant cases, the oscillations of considerable amplitude can persist…

Quantum Physics · Physics 2007-05-23 V. V. Dobrovitski , H. A. De Raedt , M. I. Katsnelson , B. N. Harmon

We show that several classes of mixed quantum states in finite-dimensional Hilbert spaces which can be characterized as being, in some respect, 'most classical' can be described and analyzed in a unified way. Among the states we consider…

Quantum Physics · Physics 2013-05-29 Marek Kuś , Ingemar Bengtsson