André Perrin

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We have studied two-body correlations of atoms in an expanding cloud above and below the Bose-Einstein condensation threshold. The observed correlation function for a thermal cloud shows a bunching behavior, whereas the correlation is flat for a coherent sample. These quantum correlations are the atomic analog of the Hanbury Brown Twiss effect. We observed(More)
We present a novel imaging system for ultracold quantum gases in expansion. After release from a confining potential, atoms fall through a sheet of resonant excitation laser light and the emitted fluorescence photons are imaged onto an amplified CCD camera using a high numerical aperture optical system. The imaging system reaches an extraordinary dynamic(More)
Fifty years ago, Hanbury Brown and Twiss (HBT) discovered photon bunching in light emitted by a chaotic source, highlighting the importance of two-photon correlations and stimulating the development of modern quantum optics. The quantum interpretation of bunching relies on the constructive interference between amplitudes involving two indistinguishable(More)
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Silver molybdate (Ag2MoO4) and silver tungstate (Ag2WO4) nanomaterials were prepared using two complementary methods, microwave assisted hydrothermal synthesis (MAH) (pH 7, 140 °C) and co-precipitation (pH 4, 70 °C), and were(More)
Seasonally-resolved upper tropospheric profiles of formaldehyde (HCHO) observed by the ACE Fourier transform spectrometer (ACE-FTS) on a near-global scale are presented for the time period from March 2004 to Novem-ber 2006. Large upper tropospheric HCHO mixing ratios (>150 pptv) are observed during the growing season of the terrestrial biosphere in the(More)
The Fourier transform spectrometer MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) on Envisat measures infrared emission of the Earth's atmosphere in a limb viewing mode. Vertical profiles of temperature and numerous trace gases are retrieved with the IMK science-oriented processor. The main sources of formaldehyde (CH O) in the(More)
Fifty years ago, Hanbury Brown and Twiss (HBT) discovered photon bunching in light emitted by a chaotic source 1 , highlighting the importance of two-photon correlations 2 and stimulating the development of modern quantum optics 3. The quantum interpretation of bunching relies upon the constructive interference between amplitudes involving two(More)
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