Nuclear Mean Fields through Selfconsistent Semiclassical Calculations

Semiclassical expansions derived in the framework of the Extended Thomas-Fermi approach for the kinetic energy density tau(r) and the spin-orbit density J(r) as functions of the local density rho(r) are used to determine the central nuclear potentials V_n(r) and V_p(r) of the neutron and proton distribution for effective interactions of the Skyrme type. We demonstrate that the convergence of the resulting semiclassical expansions for these potentials is fast and that they reproduce quite accurately the corresponding Hartree-Fock average fields.Comment: LATEX, 25 pages, including 11 eps figures. to be published in Europ. Phys. Journal

Zero supermode-based multipartite entanglement in χ(2)\chi^{(2)} nonlinear waveguides arrays

We show that arrays of $\chi^{(2)}$ nonlinear waveguides in the second harmonic generation regime are a promising source of continuous-variable entanglement. We indeed demonstrate analytically that optical arrays with odd number of waveguides injected with the zero-eigenvalue fundamental supermode entangle this fundamental supermode with a collective harmonic field. Moreover the fundamental individual modes are multipartite entangled and their entanglement grows with propagation length. The device is scalable, robust to losses, does not rely on specific values of nonlinearity and coupling and is easily realized with current technology. It thus stands as an unprecedented candidate for generation of multipartite continuous-variable entanglement for optical quantum information processing.Comment: Main text: 7 pages, 6 figures. Supplemental material: 5 pages, 2 figure. v2 closer to published versio

Coupling quasi-phase matching: entanglement buildup in χ(2)\chi^{(2)} nonlinear waveguide arrays

Wavevector quasi-phase matching was devised in the 1960s as a way to boost nonlinear interactions with efficient quantum noise squeezing as one outstanding outcome. In the era of quantum technologies, we propose a new coupling quasi-phase matching for efficient generation of multimode downconverted quantum light in nonlinear waveguide arrays. We highlight this technique achieving multimode quantum entanglement and Einstein-Podolsky-Rosen steering buildup. We discuss the feasibility of this method with current technology and demonstrate its competitiveness as a resource for continuous variables quantum information.Comment: 9 pages, 5 figures, v2 closer to published versio

Temperature dependence of persistent spin currents in a spin-orbit-coupled electron gas: A density-matrix approach

URL:http://link.aps.org/doi/10.1103/PhysRevB.77.155315 DOI:10.1103/PhysRevB.77.155315We present a simple analytical method, based on the canonical density matrix, for the calculation of the equilibrium spin current as a function of temperature in a two- dimensional electron gas with both Rashba and Dresselhaus spin-orbit coupling terms. We find that the persistent spin current is extremely robust against thermal disorder: its variation with temperature is exponentially small (∝e−TF∕T) at temperatures much smaller than the Fermi temperature TF and changes to a power law TF∕T for T⪢TF

Contrôle de gestion et pilotage de la per-formance de l’université : une étude explo-ratoire au sein des Universités Marocaines

L'objet de notre papier est d'étudier la nécessité de contrôle de gestion dans les Universités Marocaines, organisations à vocation public ayant pour mission la recherche et l’offre de formation. D'où la question principale de la recherche : Dans quelle mesure le système de contrôle de gestion serait-il nécessaire pour le pilotage de la performance des Universités Marocaines en contexte d’autonomie et de contractualisation? Pour répondre à cette question, nous avons mobilisé à la fois la littérature en contrôle de gestion et la littérature en management public. Cette double approche théorique a permis de construire des grilles de lecture théoriques quant aux facteurs et aux préalables de la mise en place d’un système de contrôle de gestion.The object of our pa-per is to study the necessity of man-agement control in the Moroccan Uni-versities, organizations which are of public vocation and having for mission research and offer of formation. It is from here that stems the principal ques-tion of the research, namely to what extent the system of management con-trol would be necessary for perfor-mance guiding in terms of Moroccan Universities’ autonomy and contracting. To answer this question we have mobi-lized both the literature of management control and that of public management. This double theoretical approach has permitted us to establish theoretical reading grids relative to factors and pri-or conditions for the setting up of a management control system

Ultraslow light propagation in an inhomogeneously broadened rare-earth ion-doped crystal

We show that Coherent Population Oscillations effect allows to burn a narrow spectral hole (26Hz) within the homogeneous absorption line of the optical transition of an Erbium ion-doped crystal. The large dispersion of the index of refraction associated with this hole permits to achieve a group velocity as low as 2.7m/s with a ransmission of 40%. We especially benefit from the inhomogeneous absorption broadening of the ions to tune both the transmission coefficient, from 40% to 90%, and the light group velocity from 2.7m/s to 100m/s

Continuous-variable entanglement of two bright coherent states that never interacted

We study continuous-variable entanglement of bright quantum states in a pair of evanescently coupled nonlinear $\chi^{(2)}$ waveguides operating in the regime of degenerate down-conversion. We consider the case where only the energy of the nonlinearly generated fields is exchanged between the waveguides while the pump fields stay independently guided in each original waveguide. We show that this device, when operated in the depletion regime, entangles the two non-interacting bright pump modes due to a nonlinear cascade effect. It is also shown that two-colour quadripartite entanglement can be produced when certain system parameters are appropriately set. This device works in the traveling-wave configuration, such that the generated quantum light shows a broad spectrum. The proposed device can be easily realized with current technology and therefore stands as a good candidate for a source of bipartite or multipartite entangled states for the emerging field of optical continuous-variable quantum information processing.Comment: 10 pages, 12 figure