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It is shown that the von Neumann entropy, a measure of quantum entanglement, does have its classical counterpart in thermodynamic systems, which we call partial entropy. Close to the critical temperature the partial entropy shows perfect…

Strongly Correlated Electrons · Physics 2009-11-11 Junpeng Cao , Xiaoling Cui , Zhang Qi , Wengang Lu , Qian Niu , Yupeng Wang

In the framework of the Lindblad theory for open quantum systems, expressions for the density operator, von Neumann entropy and effective temperature of the damped harmonic oscillator are obtained. The entropy for a state characterized by a…

Quantum Physics · Physics 2015-06-26 A. Isar

Thermodynamic irreversibility is well characterized by the entropy production arising from non-equilibrium quantum processes. We show that the entropy production of a quantum system undergoing open-system dynamics can be formally split into…

Quantum Physics · Physics 2019-07-02 Jader P. Santos , Lucas C. Céleri , Gabriel T. Landi , Mauro Paternostro

This study discusses the quantum behavior of a particle, which is controlled by fluctuations in the physical space-time (ST) variables, rather than provides a novel interpretation of quantum theory. The fluctuations, i.e., inhomogeneities…

General Physics · Physics 2012-06-15 Valery Egorushkin

In quantum mechanics without application of any superselection rule to the set of the observables, a closed quantum system temporally evolves unitarily, and this Lorentzian regime is characterized by von Neumann entropy of exactly zero. In…

Quantum Physics · Physics 2023-04-03 Eiji Konishi

We investigate temporal evolution of von Neumann's entropy in exemplary quantum mechanical systems and show that it grows in systems evolving with incrementally increasing decoherence during scattering processes. We demonstrate that the…

Quantum Physics · Physics 2013-12-30 G. B. Lesovik , I. A. Sadovskyy , A. V. Lebedev , M. V. Suslov , V. M. Vinokur

We discuss a general notion of quantum correlations in fermionic or bosonic indistinguishable particles. Our approach is mainly based on the identification of the algebra of single-particle observables, which allows us to devise an…

Quantum Physics · Physics 2014-03-18 Fernando Iemini , Tiago Debarba , Reinaldo O. Vianna

The von Neumann entropy of various quantum dissipative models is calculated in order to discuss the entanglement properties of these systems. First, integrable quantum dissipative models are discussed, i.e., the quantum Brownian motion and…

Quantum Physics · Physics 2009-11-11 T. Stauber , F. Guinea

Statistical formulations of thermodynamic entropy, such as those by Boltzmann and Gibbs, were originally developed for classical systems and are well understood in that context. However, the foundational aspects of quantum statistical…

Quantum Physics · Physics 2025-10-08 Smitarani Mishra , Shaon Sahoo

The entanglement entropy of a pure quantum state of a bipartite system is defined as the von Neumann entropy of the reduced density matrix obtained by tracing over one of the two parts. Critical ground states of local Hamiltonians in one…

Strongly Correlated Electrons · Physics 2016-09-08 Eduardo Fradkin

Entropy production is a fundamental concept that plays a crucial role in the second law of thermodynamics and the measure of irreversibility. It imposes rigorous constraints on the kinds of transformations allowed in thermodynamic…

Quantum mechanics emerges a la Verlinde from a foliation of space by holographic screens, when regarding the latter as entropy reservoirs that a particle can exchange entropy with. This entropy is quantised in units of Boltzmann's constant…

High Energy Physics - Theory · Physics 2011-09-21 D. Acosta , P. Fernandez de Cordoba , J. M. Isidro , J. L. G. Santander

We show that partial transposition for pure and mixed two-particle states in a discrete $N$-dimensional Hilbert space is equivalent to a change in sign of a "momentum-like" variable of one of the particles in the Wigner function for the…

Quantum Physics · Physics 2017-05-29 Yehuda B. Band , Pier A. Mello

For a quantum state undergoing unitary Schr\"odinger time evolution, the von Neumann entropy is constant. Yet the second law of thermodynamics, and our experience, show that entropy increases with time. Ingarden introduced the quantum…

Quantum Physics · Physics 2019-07-03 Craig S. Lent

The study of conditional $q$-entropies in composite quantum systems has recently been the focus of considerable interest, particularly in connection with the problem of separability. The $q$-entropies depend on the density matrix $\rho$…

Quantum Physics · Physics 2009-11-10 J. Batle , A. R. Plastino , M. Casas , A. Plastino

We relate the notion of entanglement for quantum systems composed of two identical constituents to the impossibility of attributing a complete set of properties to both particles. This implies definite constraints on the mathematical form…

Quantum Physics · Physics 2007-05-23 GianCarlo Ghirardi , Luca Marinatto

We present a new approach to analyze homogeneous nucleation based on non-equilibrium thermodynamics. The starting point is the formulation of a Gibbs equation for the variations of the entropy of the system, whose state is characterized by…

Condensed Matter · Physics 2007-05-23 D. Reguera Lopez , J. M. Rubi , A. Perez-Madrid

We investigate the basic theoretical issues in the quantum entanglement of particle pairs created from the vacuum in a time-dependent background field or spacetime. Similar to entropy generation from these processes which depends on the…

General Relativity and Quantum Cosmology · Physics 2010-05-07 Shih-Yuin Lin , Chung-Hsien Chou , B. L. Hu

The entanglement entropy of a pure quantum state of a bipartite system $A \cup B$ is defined as the von Neumann entropy of the reduced density matrix obtained by tracing over one of the two parts. Critical ground states of local…

Strongly Correlated Electrons · Physics 2008-11-26 Eduardo Fradkin , Joel E. Moore

We extend on ideas from standard thermodynamics to show that temperature can be assigned to a general nonequilibrium quantum system. By choosing a physically motivated complete set of observables and expanding the system state thereupon,…

Quantum Physics · Physics 2021-05-26 S. Alipour , F. Benatti , M. Afsary , F. Bakhshinezhad , M. Ramezani , T. Ala-Nissila , A. T. Rezakhani