Search results for "concurrence"
showing 10 items of 53 documents
De la régionalisation à la concurrence régulée. Analyse économique et juridique de la future organisation du transport ferroviaire régional de voyage…
2006
This paper deals with the introduction of competition for the market in French regional passenger railways. Following a double approach through economics and law, it discusses the proposals for a European regulation on public passenger transport services. In a first part, the paper explains the interest and limits of competition for the market concerning French regional rail services. After analyzing the German and Swedish cases, it proposes a way of introducing competition for the market in France. In a second part, structural reforms needed ex ante are analyzed: open access to stations, rolling stock availability and future of rail employees. For each reform, the theoretical analysis is f…
Asymptotic entanglement of two atoms in a squeezed light field
2011
The dynamics of entanglement between two - level atoms interacting with a common squeezed reservoir is investigated. It is shown that for spatially separated atoms there is a unique asymptotic state depending on the distance between the atoms and the atom - photons detuning. In the regime of strong correlations there is a one - parameter family of asymptotic steady - states depending on initial conditions. In contrast to the thermal reservoir both types of asymptotic states can be entangled. We calculate the amount of entanglement in the system in terms of concurrence.
Tripartite thermal correlations in an inhomogeneous spin-star system
2010
We exploit the tripartite negativity to study the thermal correlations in a tripartite system, that is the three outer spins interacting with the central one in a spin-star system. We analyze the dependence of such correlations on the homogeneity of the interactions, starting from the case where central-outer spin interactions are identical and then focusing on the case where the three coupling constants are different. We single out some important differences between the negativity and the concurrence.
Transfer of powers and reallocation of the social capital available to junior governments
1993
The article starts from the assumption that the production of junior governments in sub-central jurisdictions such as the department of the region is related both to the powers or resources that they receive from the central government and to the social capital which is available to them. A model is proposed in which both elements are considered as factors o f production. The second being able to move only slowly across levels of jurisdiction, the central government is itself unable to transfer rapidly powers or resources from one level to another without running the risk of an efficiency loss of the whole which it would find unacceptable in terms of electoral support.
Dynamique concurrentielle des petits distributeurs indépendants en milieu urbain : une dynamique bien peu concurrentielle !
2020
International audience
Première victoire pour Yuka !
2023
Observations sous Aix-en-Provence, ch. 3-1, 8 déc. 2022, no 2022/354 - Qualification de la décision : Importante
Les effets pervers de la mise en marché des établissements
1997
National audience; Les leçons de l'exemple britannique que tire une des chercheuses qui a le plus développé la notion d'effet-établissement. Des avertissements salutaires alors qu'ici ou là, dans les milieux libéraux, on encense le "modèle anglais"
On the validity of non-Markovian master equation approaches for the entanglement dynamics of two-qubit systems
2010
In the framework of the dissipative dynamics of coupled qubits interacting with independent reservoirs, a comparison between non-Markovian master equation techniques and an exact solution is presented here. We study various regimes in order to find the limits of validity of the Nakajima–Zwanzig and the time-convolutionless master equations in the description of the entanglement dynamics. A comparison between the performances of the concurrence and the negativity as entanglement measures for the system under study is also presented.
Nonlocality threshold for entanglement under general dephasing evolutions: A case study
2015
Determining relationships between different types of quantum correlations in open composite quantum systems is important since it enables the exploitation of a type by knowing the amount of another type. We here review, by giving a formal demonstration, a closed formula of the Bell function, witnessing nonlocality, as a function of the concurrence, quantifying entanglement, valid for a system of two noninteracting qubits initially prepared in extended Werner-like states undergoing any local pure-dephasing evolution. This formula allows for finding nonlocality thresholds for the concurrence depending only on the purity of the initial state. We then utilize these thresholds in a paradigmatic …
Heat Capacity and entanglement
2012
Starting from a recent result on thermodynamic equilibrium of quantum systems, a connection between thermal properties, originating from Gibbs state probabilistic structure, and quantum correlations is discussed as a consequence of entanglement monogamy. As an example, a simple two-qubit system is analyzed, allowing for an expression of such a connection as an explicit function linking heat capacity to a measure of bipartite entanglement.