2,022 research outputs found
Séminaire de synthèse : guide pédagogique à l'intention des professeurs des techniques d'éducation en services de garde du réseau collégial /
No full textBibliogr.: f. 41Médiagraphie: f. 4
Dr R. Le Bec. Raisons médicales de croire au miracle, 1950
No full textN. M. Dr R. Le Bec. Raisons médicales de croire au miracle, 1950. In: Revue des Sciences Religieuses, tome 25, fascicule 2, 1951. p. 215
Ginzburg-Landau theory of a trapped Fermi gas with a BEC-BCS crossover
No full textThe Ginzburg-Landau theory of a trapped Fermi gas with a BEC-BCS crossover is derived by the path-integral method. In addition to the standard Ginzburg-Landau equation, a second equation describing the total atom density is obtained. These two coupled equations are necessary to describe both homogeneous and inhomogeneous systems. The Ginzburg-Landau theory is valid near the transition temperature T(c) on both sides of the crossover. In the weakly interacting BEC region, it is also accurate at zero temperature where the Ginzburg-Landau equation can be mapped onto the Gross-Pitaevskii (GP) equation. The applicability of GP equation at finite temperature is discussed. On the BEC side, the fluctuation of the order parameter is studied and the renormalization to the molecule coupling constant is obtained.OpticsPhysics, Atomic, Molecular & ChemicalSCI(E)EI5ARTICLE5null7
Three-dimensional structure of quantized vortices in rotating Bose-Einstein condensates
No full textBose-Einstein condensates (BEC) are ideal superfluid systems to realize quantum turbulence (QT): vortex cores in BECs are larger than in superfluid Helium, making easier their observation. Recent experimental and numerical studies reported that vortex states in BEC can evolve towards a turbulent regime when an oscillatory excitation is applied. We discuss in this work how to accurately prepare initial states with vortices before running numerical simulations of QT based on the Gross-Pitaevskii equation. The case of a dense Abrikosov lattice in a fast rotating BEC is presented. High resolution numerical simulations using parallel computing are used to accurately capture physically important features of the vortices (vortex radius, inter-vortex spacing, vortex density profile)
Business Research: BEC 322E
No full textBusiness Research: BEC 322E, supplementary examination January 2012
Business Research: BEC 321
No full textBusiness Research: BEC 321, supplementary examination January 2012
Business Research: BEC 321 & 321
No full textExamination on Business Research: BEC 321& 321- November 2009
Relativistic description of BCS–BEC crossover in nuclear matter
No full textAbstractWe study theoretically the di-neutron spatial correlations and the crossover from superfluidity of neutron Cooper pairs in the S01 pairing channel to Bose–Einstein condensation (BEC) of di-neutron pairs for both symmetric and neutron matter in the microscopic relativistic pairing theory. We take the bare nucleon–nucleon interaction Bonn-B in the particle–particle channel and the effective interaction PK1 of the relativistic mean-field approach in the particle–hole channel. It is found that the spatial structure of neutron Cooper pair wave function evolves continuously from BCS-type to BEC-type as density decreases. We see a strong concentration of the probability density revealed for the neutron pairs in the fairly small relative distance around 1.5 fm and the neutron Fermi momentum kFn∈[0.6,1.0] fm−1. However, from the effective chemical potential and the quasiparticle excitation spectrum, there is no evidence for the appearance of a true BEC state of neutron pairs at any density. The most BEC-like state may appear at kFn∼0.2 fm−1 by examining the density correlation function. From the coherence length and the probability distribution of neutron Cooper pairs as well as the ratio between the neutron pairing gap and the kinetic energy at the Fermi surface, some features of the BCS–BEC crossover are seen in the density regions, 0.05 fm−1<kFn<0.7(0.75) fm−1, for the symmetric nuclear (pure neutron) matter
The magnon BEC observation by switch off method
No full textThe Bose–Einstein condensation (BEC) corresponds to the formation of a collective quantum state in which macroscopic number of particles is governed by a single wave function. The magnon BEC forms by excited non-equilibrium magnons and manifests itself by coherent precession of magnetization even in an inhomogeneous magnetic field. The magnon BEC is very similar to an atomic BEC, but the potential of the interaction between magnons may variate very significantly. The superfluid phases of 3He are the best antiferromagnetic system for investigations of magnon BEC and spin superfluidity. The 6 different states of magon BEC were observed in 3He. Recently magnon BEC was observed in antiferromagnets with Suhl–Nakamura interaction and ferrites. Here we review for the first time the switch off NMR method, when magnon BEC forms during a long radiofrequency pulse. The new experimental results are discussed.The author thanks to a discussions with my colleges in the laboratory of non-linear magnetic resonance and spin superfluidity of Kazan Federal University and in Ultra Low Temperature group of the Institute Neel, Grenoble, France. This work was financially supported by the Russian Science Foundation (Grant No. RSF 16-12-10359)
Marketing Management: BEC 221 & 221E
No full textMarketing Management: BEC 221 & 221E, Supplementary examination, February 201
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