Results
repositories = "HAL - Hyper Article on Line"
> : "BEC"
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Bose-Einstein condensation on a superconducting atom chip
Author(s) :
Roux, Cédric
,
Emmert, Andreas
,
Lupascu, Adrian
,
Nirrengarten, Thomas
,
Nogues, G.
,
Brune, Michel
,
Raimond, Jean-Michel
Description :
We have produced a Bose-Einstein condensate (BEC) on an atom chip using only superconducting wires in a cryogenic environment. We observe the onset of condensation for 1·10^4 atoms at a temperature of 100 nK. This result opens the way for studies of atom losses and decoherence in a BEC interacting w...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Du sillage des insectes aux gaz de Fermi ultra-froids : dynamique des fluides classiques et quantiques
Author(s) :
Chevy, Frédéric
Description :
Dans cette exposé, je présenterai quelques résultats théoriques et expérimentaux sur la dynamique des fluides classiques et quantiques. Dans une première partie, je présenterai un bref exposé sur la nucléation de gouttes de pluie en montrant le rôle de l'instabilité classique de Rayleigh Taylor dans...
Repository :
HAL - Hyper Article on Line
Language(s) :
French
Pseudopotential in resonant regimes
Author(s) :
Pricoupenko, Ludovic
Description :
The zero-range potential approach is extended for the description of situations where two-body scattering is resonant in arbitrary partial waves. The formalism generalizes the Fermi pseudopotential which can be used only for s-wave broad resonances. In a given channel, the interaction is described e...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Population and Phase Coherence during the Growth of an Elongated Bose-Einstein Condensate
Author(s) :
Hugbart, Mathilde
,
Retter, Jocelyn A.
,
Varòn, Andrès
,
Bouyer, Philippe
,
Aspect, Alain
,
Davis, Matthew
Description :
We study the growth of an elongated phase-fluctuating condensate from a non-equilibrium thermal cloud obtained by shock-cooling. We compare the growth of the condensate with numerical simulations, revealing a time delay and a reduction in the growth rate which we attribute to phase fluctuations. We ...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Schemes for loading a Bose-Einstein condensate into a two-dimensional dipole trap
Author(s) :
Colombe, Yves
,
Kadio, Demascoth
,
Olshanii, Maxim
,
Mercier, Brigitte
,
Lorent, Vincent
,
Perrin, Hélène
Description :
We propose two loading mechanisms of a degenerate Bose gas into a surface trap. This trap relies on the dipole potential produced by two evanescent optical waves far detuned from the atomic resonance, yielding a strongly anisotropic trap with typical frequencies 40 Hz x 65 Hz x 30 kHz. We present nu...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Expansion of a lithium gas in the BEC-BCS crossover
Author(s) :
Zhang, J.
,
Van Kempen, E.G.M.
,
Bourdel, T.
,
Khaykovich, L.
,
Cubizolles, J.
,
Chevy, F.
,
Teichmann, M.
,
Tarruell, L.
Description :
We report on experiments in $^6$Li Fermi gases near Feshbach resonances. A broad $s$-wave resonance is used to form a Bose-Einstein condensate of weakly bound $^6$Li$_2$ molecules in a crossed optical trap. The measured molecule-molecule scattering length of $170^{+100}_{-60}$\,nm at 770\,G is found...
Repository :
HAL - Hyper Article on Line
Language(s) :
Undetermined
NMR evidence for a strong modulation of the Bose-Einstein Condensate in BaCuSi$_2$O$_6$
Description :
We present a $^{63,65}$Cu and $^{29}$Si NMR study of the quasi-2D coupled spin 1/2 dimer compound BaCuSi$_2$O$_6$ in the magnetic field range 13-26 T and at temperatures as low as 50~mK. NMR data in the gapped phase reveal that below 90~K different intra-dimer exchange couplings and different gaps (...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Number of closed-channel molecules in the BEC-BCS crossover
Description :
Using a two-channel model, we show that the number of closed channel molecules in a two-component Fermi gas close to a Feshbach resonance is directly related to the derivative of the energy of the gas with respect to the inverse scattering length. We extract this quantity from the fixed node Monte-C...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
The Equation of State of a Low-Temperature Fermi Gas with Tunable Interactions
Description :
Interacting fermions are ubiquitous in nature and understanding their thermodynamics is an important problem. We measure the equation of state of a two-component ultracold Fermi gas for a wide range of interaction strengths at low temperature. A detailed comparison with theories including Monte-Carl...
Repository :
HAL - Hyper Article on Line
Language(s) :
English
Elastic scattering of a quantum matter-wave bright soliton on a barrier
Description :
We consider a one-dimensional matter-wave bright soliton, corresponding to the ground bound state of N particles of mass m having a binary attractive delta potential interaction on the open line. For a full N-body quantum treatment, we derive several results for the scattering of this quantum solito...
Repository :
HAL - Hyper Article on Line
Language(s) :
English