Publications (37)
Specular reflection of matter waves from a rough mirror
V. Savalli, D. Stevens, J. Esteve +4
We have made a high resolution study of the specularity of the atomic reflection from an evanescent wave mirror using velocity selective Raman transitions. We have observed a doubl…
RF-induced evaporative cooling and BEC in a high magnetic field
P. Bouyer, V. Boyer, S. G. Murdoch +4
We present the design of our iron-core electromagnet for BEC, and how to solve the specific experimental problems raised by this technique. After presenting the experimental set-up…
Properties of Microelectromagnet Mirrors as Reflectors of Cold Rb Atoms
M. Drndic, G. Zabow, C. S. Lee +12
Cryogenically cooled microelectromagnet mirrors were used to reflect a cloud of free-falling laser-cooled 85Rb atoms at normal incidence. The mirrors consisted of microfabricated c…
Quasi-continuous atom laser in the presence of gravity
F. Gerbier, P. Bouyer, A. Aspect
We analyse the extraction of a coherent atomic beam from a trapped Bose-Einstein condensate using a rf transition to a non-trapping state at T=0 K. Our quantum treatment fully take…
Resolved diffraction patterns from a reflection grating for atoms
J. Esteve, D. Stevens, V. Savalli +3
We have studied atomic diffraction at normal incidence from an evanescent standing wave with a high resolution using velocity selective Raman transitions. We have observed up to 3…
An oscillator circuit to produce a radio-frequency discharge and application to metastable helium saturated absorption spectroscopy
F. Moron, A. L. Hoendervanger, M. Bonneau +5
We present an rf gas discharge apparatus which provides an atomic frequency reference for laser manipulation of metastable helium. We discuss the biasing and operation of a Colpitt…
Momentum spectroscopy of 1D phase fluctuations in Bose-Einstein condensates
S. Richard, F. Gerbier, J. H. Thywissen +3
We measure the axial momentum distribution of Bose-Einstein condensates with an aspect ratio of 152 using Bragg spectroscopy. We observe the Lorentzian momentum distribution charac…
Ionization rates in a Bose-Einstein condensate of metastable Helium
O. Sirjean, S. Seidelin, J. Viana Gomes +4
We have studied ionizing collisions in a BEC of He*. Measurements of the ion production rate combined with measurements of the density and number of atoms for the same sample allow…
Hanbury Brown and Twiss correlations in atoms scattered from colliding condensates
Klaus Molmer, A. Perrin, V. Krachmalnicoff +4
Low energy elastic scattering between clouds of Bose condensed atoms leads to the well known s-wave halo with atoms emerging in all directions from the collision zone. In this pape…
Thermal counting statistics in an atomic two-mode squeezed vacuum state
M. Perrier, Z. Amodjee, P. Dussarrat +5
We measure the population distribution in one of the atomic twin beams generated by four-wave mixing in an optical lattice. Although the produced two-mode squeezed vacuum state is…
All-optical runaway evaporation to Bose-Einstein condensation
Jean-Francois Clément, Jean-Philippe Brantut, Martin Robert De Saint Vincent +4
We demonstrate runaway evaporative cooling directly with a tightly confining optical dipole trap and achieve fast production of condensates of 1.5x10^5 87Rb atoms. Our scheme is ch…
Transport regimes of cold gases in a two-dimensional anisotropic disorder
L. Pezze, M. Robert-de-Saint-Vincent, T. Bourdel +6
We numerically study the dynamics of cold atoms in a two-dimensional disordered potential. We consider an anisotropic speckle potential and focus on the classical regime, which is…
Using atomic interference to probe atom-surface interaction
R. Marani, L. Cognet, V. Savalli +3
We show that atomic interference in the reflection from two suitably polarized evanescent waves is sensitive to retardation effects in the atom-surface interaction for specific exp…
Observation of atom pairs in spontaneous four wave mixing of two colliding Bose-Einstein Condensates
A. Perrin, H. Chang, V. Krachmalnicoff +4
We study atom scattering from two colliding Bose-Einstein condensates using a position sensitive, time resolved, single atom detector. In analogy to quantum optics, the process can…
Momentum distribution and correlation function of quasicondensates in elongated traps
F. Gerbier, J. H. Thywissen, S. Richard +3
We calculate the spatial correlation function and momentum distribution of a phase-fluctuating, elongated three-dimensional condensate, in a trap and in free expansion. We take the…
Phase shifts of atomic de Broglie waves at an evanescent wave mirror
C. Henkel, J. -Y. Courtois, R. Kaiser +2
A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of t…
Fast production of Bose-Einstein condensates of metastable Helium
Q. Bouton, R. Chang, A. L. Hoendervanger +4
We report on the Bose-Einstein condensation of metastable Helium-4 atoms using a hybrid approach, consisting of a magnetic quadrupole and a crossed optical dipole trap. In our setu…
Momentum Spectroscopy of Phase Fluctuations of an Elongated Bose-Einstein Condensate
A. Aspect, S. Richard, F. Gerbier +4
We have measured the momentum distribution of an elongated BEC (aspect ratio of 152), for temperatures below the critical temperature. The corresponding coherence length is signifi…
Understanding the production of dual BEC with sympathetic cooling
G. Delannoy, S. G. Murdoch, V. Boyer +3
We show, both experimentally and theoretically, that sympathetic cooling of Rb atoms in the state by evaporatively cooled atoms in the state can…
Phase coherence length of a Bose-Einstein condensate
F. Gerbier, S. Richard, J. H. Thywissen +3
We report on the measurement of the momentum distribution of an elongated Bose-Einstein condensate. A broadening of the distribution with increasing temperature is observed, which…
Atom laser divergence
Y. Le Coq, J. H. Thywissen, S. A. Rangwala +5
We measure the angular divergence of a quasi-continuous, rf-outcoupled, free-falling atom laser as a function of the outcoupling frequency. The data is compared to a Gaussian-beam…
Gray molasses cooling of K to a high phase-space density
G. Salomon, L. Fouché, P. Wang +3
We present new techniques in cooling 39K atoms using laser light close to the D1 transition. First, a new compressed-MOT configuration is taking advantage of gray molasses type coo…
Expansion of a matter wave packet in a one-dimensional disordered potential in the presence of a uniform bias force
C Crosnier de Bellaistre, C Trefzger, A. Aspect +2
We study numerically the expansion dynamics of an initially confined quantum wave packet in the presence of a disordered potential and a uniform bias force. For white-noise disorde…
Atomic diffraction by a thin phase grating
C. Henkel, J. -Y. Courtois, A. Aspect
We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light dif…
Theoretical tools for atom laser beam propagation
J. -F. Riou, Y. Le Coq, F. Impens +4
We present a theoretical model for the propagation of non self-interacting atom laser beams. We start from a general propagation integral equation, and we use the same approximatio…
Hanbury Brown Twiss effect for ultracold quantum gases
M. Schellekens, R. Hoppeler, A. Perrin +4
We have studied 2-body correlations of atoms in an expanding cloud above and below the Bose-Einstein condensation threshold. The observed correlation function for a thermal cloud s…
Multi frequency evaporative cooling to BEC in a high magnetic field
V. Boyer, S. Murdoch, Y. Le Coq +3
We demonstrate a way to circumvent the interruption of evaporative cooling observed at high bias field for Rb atoms trapped in the (F=2, m=+2) ground state. Our scheme uses…
Phase locking a clock oscillator to a coherent atomic ensemble
R. Kohlhaas, A. Bertoldi, E. Cantin +3
The sensitivity of an atomic interferometer increases when the phase evolution of its quantum superposition state is measured over a longer interrogation interval. In practice, a l…
Single photon wavefront-splitting interference: An illustration of the light quantum in action
V. Jacques, E. Wu, T. Toury +4
We present a new realization of the textbook experiment consisting in single-photon interference based on the pulsed, optically excited photoluminescence of a single colour centre…
Bose-Einstein condensation of metastable helium: some experimental aspects
C. I. Westbrook, A. Robert, O. Sirjean +3
We describe our recent realization of BEC using metastable helium. All detection is done with a micruchannel plate which detects the metastables or ions coming from the trapped ato…
One-dimensional behavior of elongated Bose-Einstein condensates
P. Bouyer, J. H. Thywissen, F. Gerbier +4
We study the properties of elongated Bose-Einstein condensates. First, we show that the dimensions of the condensate after expansion differs from the 3D Thomas-Fermi regime. We als…
Guided atom laser : a new tool for guided atom optics
J. Billy, V. Josse, Z. Zuo +3
We present a guided atom laser. A Bose-Einstein condensate (BEC) is created in a crossed hybrid magnetic and an elongated optical trap, which acts as a matterwave guide. Atoms are…
Using ion production to monitor the birth and death of a metastable helium Bose-Einstein condensate
S. Seidelin, O. Sirjean, J. Viana Gomes +3
We discuss observations of the ion flux from a cloud of trapped metastable helium atoms. Both Bose-Einstein condensates and thermal clouds were investigated. The ion flux is compar…
Momentum-resolved observation of thermal and quantum depletion in an interacting Bose gas
R. Chang, Q. Bouton, H. Cayla +4
We report on the single-atom-resolved measurement of the distribution of momenta in a weakly interacting Bose gas after a 330 ms time-of-flight. We investigate it for var…
Thermalization of magnetically trapped metastable helium
A. Browaeys, A. Robert, O. Sirjean +5
We have observed thermalization by elastic collisions of magnetically trapped metastable helium atoms. Our method directly samples the reconstruction of a thermal energy distributi…
Anisotropic 2D diffusive expansion of ultra-cold atoms in a disordered potential
M. Robert-de-Saint-Vincent, J. -P. Brantut, B. Allard +6
We study the horizontal expansion of vertically confined ultra-cold atoms in the presence of disorder. Vertical confinement allows us to realize a situation with a few coupled harm…
Feedback control of trapped coherent atomic ensembles
T. Vanderbruggen, R. Kohlhaas, A. Bertoldi +4
We demonstrate how to use feedback to control the internal states of trapped coherent ensembles of two-level atoms, and to protect a superposition state against the decoherence ind…