排序方式: 共有43条查询结果,搜索用时 46 毫秒
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Sanchez-Palencia L Clément D Lugan P Bouyer P Shlyapnikov GV Aspect A 《Physical review letters》2007,98(21):210401
We show that the expansion of an initially confined interacting 1D Bose-Einstein condensate can exhibit Anderson localization in a weak random potential with correlation length sigma(R). For speckle potentials the Fourier transform of the correlation function vanishes for momenta k>2/sigma(R) so that the Lyapunov exponent vanishes in the Born approximation for k>1/sigma(R). Then, for the initial healing length of the condensate xi(in)>sigma(R) the localization is exponential, and for xi(in)相似文献
3.
Savalli V Horvath GZ Featonby PD Cognet L Westbrook N Westbrook CI Aspect A 《Optics letters》1999,24(22):1552-1554
We have demonstrated nondestructive detection of cold atoms with a probe laser by a frequency-modulation spectroscopy technique. We were able to tune the probe laser and its sidebands far from atomic resonance to reduce the spontaneous emission to less than 0.2 photon per atom during detection. 相似文献
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The two photon coincidence technique yields an absolute measurement of a cascade decay rate without knowing the detection efficiency of each detector. This method is applied to calcium atoms in an atomic beam excited to the 4p21S0 state, and decaying via the resonant 1P1 state; it yields the excitation rate of the upper 4p21S0 level. Since the excitation process (two photon absorption) is controlled, one can compute the excitation rate of the upper level as a function of the transition probabilities in the cascade. The lower transition is well known and we can therefore deduce the transition probability for the 4p21S0 -4s4p 1P1, transition which previously had not been accurately determined. The preliminary measurements yield a line strength s = 0.98 ± 0.3 au in good agreement with a recent measurement of the lifetime of the 4p21S0 state. 相似文献
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J.?EstèveEmail author T.?Schumm J.-B.?Trebbia I.?Bouchoule A.?Aspect C. I.?Westbrook 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,35(1):141-146
We discuss design considerations and the realization of
a magnetic double-well potential on an atom chip using
current-carrying wires. Stability requirements for the trapping
potential lead to a typical size of order microns for such a
device. We also present experiments using the device to manipulate
cold, trapped atoms. 相似文献
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By use of an atomic radiative cascade, we have been able to produce single photon states of the light. This light has been
submitted to two different experiments. The first one shows an anticorrelation on both sides of a beam splitter (corpuscle-like
behaviour). The second one yields interferences (wave-like behaviour). 相似文献
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Nontrivial symmetry of order parameters is crucial in some of the most interesting quantum many-body states of ultracold atoms as well as condensed matter systems. Examples in cold atoms include p-wave Feshbach molecules and d-wave paired states of fermions that could be realized in optical lattices in the Hubbard regime. Identifying these states in experiments requires measurements of the relative phase of different components of the entangled pair wave function. We propose and discuss two schemes for such phase-sensitive measurements, based on two-particle interference revealed in atom-atom or atomic density correlations. Our schemes can also be used for relative phase measurements for nontrivial particle-hole order parameters, such as d-density wave order. 相似文献
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A. Browaeys J. Poupard A. Robert S. Nowak W. Rooijakkers E. Arimondo L. Marcassa D. Boiron C. I. Westbrook A. Aspect 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(2):199-203
We have measured the two body loss rate in a magneto-optical trap containing triplet metastable He atoms. We find a rate constant
cm3/s at a -8 MHz detuning, with an uncertainty of a factor 2. This measurement is in disagreement with a recent experiment which
measures the absolute, ion-producing collision rate, but agrees with several other published measurements.
Received 20 April 1999 and Received in final form 12 July 1999 相似文献
9.
S. Nowak A. Browaeys J. Poupard A. Robert D. Boiron C. Westbrook A. Aspect 《Applied physics. B, Lasers and optics》2000,70(3):455-457
Metastable helium atoms were efficiently transferred from a magneto-optical trap (MOT) to a magnetic quadrupole trap, producing samples of up to 3᎒7 magnetically trapped atoms at a temperature of about 1 mK. We observe purely exponential decay of the samples with time constants of 9-10 s and derive an upper bound for the rate coefficient of inelastic Penning collisions. 相似文献
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S. Gleyzes A. El Amili R. A. Cornelussen P. Lalanne C. I. Westbrook A. Aspect J. Estève G. Moreau A. Martinez X. Lafosse L. Ferlazzo J. C. Harmand D. Mailly A. Ramdane 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(1):107-111
We study a Fabry-Perot cavity formed from a ridge waveguide on a AlGaAs substrate. We experimentally determined the propagation
losses in the waveguide at 780 nm, the wavelength of Rb atoms. We have also made a numerical and analytical estimate of the
losses induced by the presence of the gap which would allow the interaction of cold atoms with the cavity field. We found
that the intrinsic finesse of the gapped cavity can be on the order of F∼30, which, when one takes into account the losses
due to mirror transmission, corresponds to a cooperativity parameter for our system C∼1. 相似文献