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Related papers: Quantum dynamical entropy and decoherence rate

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We consider the quantum dynamical evolution of a fully-connected quantum system subjected to random projective measurements and study the first detection time of an extended subspace of the Hilbert space. Exact analytical expressions are…

Quantum Physics · Physics 2026-01-26 Giuseppe Del Vecchio Del Vecchio , Satya N. Majumdar

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

Control of open quantum dynamics is of great interest for realizing quantum technologies. Therefore, it is an important task to quantify and characterize the entropy for open quantum systems under decoherence. In this paper, we study the…

Quantum Physics · Physics 2024-05-21 Kohei Kobayashi

We investigate the role of a statistical complexity measure to assign equilibration in isolated quantum systems. While unitary dynamics preserve global purity, expectation values of observables often exhibit equilibration-like behavior,…

Quantum Physics · Physics 2025-08-14 Marcos G. Alpino , Tiago Debarba , Reinaldo O. Vianna , André T. Cesário

We report the creation of a wide range of quantum states with controllable degrees of entanglement and entropy using an optical two-qubit source based on spontaneous parametric downconversion. The states are characterised using measures of…

Quantum Physics · Physics 2009-11-07 A. G. White , D. F. V. James , W. J. Munro , P. G. Kwiat

Within the unified framework of exploiting the relative entropy as a distance measure of quantum correlations, we make explicit the hierarchical structure of quantum coherence, quantum discord and quantum entanglement in multipartite…

Quantum Physics · Physics 2015-08-19 Yao Yao , Xing Xiao , Li Ge , C. P. Sun

Quantum properties of the state associated to the gluon Green's function in the BFKL approach are studied using a discretization in virtuality space. Considering the coupling constant as imaginary, its density matrix corresponds to a pure…

High Energy Physics - Theory · Physics 2023-12-29 G. Chachamis , M. Hentschinski , A. Sabio Vera

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

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

By using relative entropy of coherence, we characterize the coherence gain induced by some quantum evolutions, including the cohering power of unitary operations and the decohering power of quantum operations. We find that the cohering…

Quantum Physics · Physics 2016-07-28 Zhengjun Xi , Mingliang Hu , Yongming Li , Heng Fan

The dynamical evolution of a quantum register of arbitrary length coupled to an environment of arbitrary coherence length is predicted within a relevant model of decoherence. The results are reported for quantum bits (qubits) coupling…

Quantum Physics · Physics 2009-11-07 John H. Reina , Luis Quiroga , Neil F. Johnson

Consider the question: what statistical ensemble corresponds to minimal prior knowledge about a quantum system ? For the case where the system is in fact known to be in a pure state there is an obvious answer, corresponding to the unique…

Quantum Physics · Physics 2009-10-31 Michael J. W. Hall

Quantitative analysis of discontinuity of basic characteristics of quantum states and channels is presented. First we consider general estimates for discontinuity jump (loss) of the von Neumann entropy for a given converging sequence of…

Quantum Physics · Physics 2021-09-28 M. E. Shirokov

We prove a quantum version of the second law of thermodynamics: the (quantum) Boltzmann entropy increases if the initial (zero time) density matrix decoheres, a condition generally satisfied in Nature. It is illustrated by a model of…

Mathematical Physics · Physics 2015-06-17 H. Narnhofer , W. F. Wreszinski

The decoherence phenomenon arising from an environmental monitoring of the state of a quantum system, as opposed to monitoring of a preferred observable, is worked out in detail using two equivalent formulations, namely, repeated…

Quantum Physics · Physics 2026-03-17 Dorje C. Brody , Rishindra Melanathuru

We investigate the system-environment information flow from the point of view ofcomplete complementarity relations. We consider some commonly used noisy quantum channels:Amplitude damping, phase damping, bit flip, bit-phase flip, phase…

Quantum Physics · Physics 2021-06-25 Marcos L. W. Basso , Jonas Maziero

Entanglement of pure states of bipartite quantum systems has been shown to have a unique measure in terms of the von Neumann entropy of the reduced states of either of its subsystems. The measure is established under entanglement…

Quantum Physics · Physics 2007-05-23 Garry Bowen , Nilanjana Datta

The second law of thermodynamics can be expressed in terms of entropy production, which can be used to quantify the degree of irreversibility of a process. In this Chapter, we consider the standard scenario of open quantum systems, where a…

Quantum Physics · Physics 2025-01-31 Giorgio Zicari , Barış Çakmak , Mauro Paternostro

The entropy of a classical thermally isolated Hamiltonian system is given by the logarithm of the measure of phase space enclosed by the constant energy hyper-surface, also known as volume entropy. It has been shown that on average the…

Statistical Mechanics · Physics 2016-10-12 Michele Campisi

I study the scaling behavior in the physical parameters of dynamical entropies, classical and quantum, in a specifically devised model of collision-induced decoherence in a chaotic system. The treatment is fully canonical and no…

Quantum Physics · Physics 2024-07-17 Giorgio Mantica