排序方式: 共有26条查询结果,搜索用时 31 毫秒
1.
Ch. Lisdat N. Vanhaecke D. Comparat P. Pillet 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):299-309
Two-photon photoassociation spectra in a Λ-type excitation scheme are analysed under the systematically varied experimental conditions of frequency detunings and laser
intensities. Line shape fits are presented as well as the investigation of intensity and detuning dependent line shifts. From
both we determine the attained spectroscopic precision, that is corrected for a systematic line shift due to the thermal distribution
of atoms in the trap. An energy correction for this effect is given. Information about the feasibility of generating translationally
cold molecules in a well defined rotational and vibrational level by the photoassociation process is derived from the analysis.
Received 21 May 2002 Published online 15 October 2002
RID="a"
ID="a"Current address e-mail: christian.lisdat@ptb.de
RID="b"
ID="b"e-mail: pierre.pillet@lac.u-psud.fr 相似文献
2.
Drag C Laburthe Tolra B T'Jampens B Comparat D Allegrini M Crubellier A Pillet P 《Physical review letters》2000,85(7):1408-1411
In photoassociation spectroscopy, the line intensities of a given vibrational progression exhibit zero-signal modulation reflecting the node structure of the s-wave ground state wave function of two free colliding atoms. This leads to the determination of the scattering length. We performed photoassociation of cold Cs atoms polarized in the Zeeman sublevel f = 4, m(f) = 4. We analyzed the intensities of the lines associated with the Cs2 0(-)(g) state dissociating to the 6s(1/2)+6p(3/2) asymptote. This yields a value of the Cs triplet state scattering length, a(T) = -530a(0), while consistency requirements impose a value of the multipole ground state molecular coefficient, C6 = 6510 a.u. 相似文献
3.
A. Fioretti D. Comparat C. Drag C. Amiot O. Dulieu F. Masnou-Seeuws P. Pillet 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(3):389-403
The photoassociative spectroscopy of the Cs2 0 g - long-range molecular state dissociating into the asymptote is performed, using cold cesium atoms in a vapor-cell magneto-optical trap (MOT). Vibrational levels from v =0 to v =132 are identified, and their rotational structure is well resolved up J =8 for levels below v =74. These data are analyzed in terms of the Rydberg-Klein-Rees (RKR) procedure, and correspond to 99.6% of an effective potential curve with a minimum at ? and a cm-1 depth. Both ab initio calculations and simple model estimations predict a double-well structure for this potential curve, which cannot be reproduced presently by the RKR approach but which is confirmed by the presence of giant structures in the spectrum. The 1u()long-range state is also observed for the first time in Cs2. 相似文献
4.
D. Sofikitis ;A. Fioretti ;S. Weber ;M. Viteau ;A. Chotia ;R. Horchani ;M. Allegrini ;B. Chatel ;D. Comparat ;P. Pillet 《化学物理学报(中文版)》2009,22(2):149-156
The use of a broadband, frequency shaped femtosecond laser on translationally cold cesium molecules has recently demonstrated to be a very efficient method of cooling also the vibrational degree of freedom. A sample of cold molecules, initially distributed over several vibrational levels, has thus been transfered into a single selected vibrational level of the singlet X^1∑g ground electronic state. Our method is based on repeated optical pumping by laser light with a spectrum broad enough to excite all populated vibrational levels but limited in its frequency bandwidth with a spatial light modulator. In such a way we are able to eliminate transitions from the selected level, in which molecules accumulate. In this paper we briefly report the main experimental results and then address, in a detailed way by computer simulations, the perspectives for a "complete" cooling of the molecules, including also the rotational degree of freedom. Since the pumping process strongly depends on the relative shape of the ground and excited potential curves, ro-vibrational cooling through different excited states is theoretically compared. 相似文献
5.
E. Brion D. Comparat G. Harel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):381-387
We present a demonstrative application of the nonholonomic control method to a real physical system composed of two cold Cesium
atoms. In particular, we show how to implement a CNOT quantum gate in this system by means of a controlled Stark field. 相似文献
6.
High resolution laser excitation of np Rydberg states of cesium atoms shows a dipole blockade at F?rster resonances corresponding to the resonant dipole-dipole energy transfer of the np+np --> ns+(n+1)s reaction. The dipole-dipole interaction can be tuned on and off by the Stark effect, and such a process, observed for relatively low n(25-41), is promising for quantum gate devices. Both Penning ionization and saturation in the laser excitation can limit the range of observation of the dipole blockade. 相似文献
7.
Coupling by the resonant dipole-dipole energy transfer between cold cesium Rydberg atoms is investigated using time-resolved narrow-band deexcitation spectroscopy. This technique combines the advantage of efficient Rydberg excitation with high-resolution spectroscopy at variable interaction times. Dipole-dipole interaction is observed spectroscopically as avoided level crossing. The coherent character of the process is linked to back and forth transfer in the np + np <--> ns + (n + 1)s reaction. Decoherence in the ensemble has two different origins: the atom motion induced by dipole-dipole interaction and the migration of the s-Rydberg excitation in the environment of p-Rydberg atoms. 相似文献
8.
Cross sections for the elastic scattering of 156 MeV protons on eleven targets ranging from 12C to 209Bi were measured and an optical model analysis has been performed. The effect of different optical potentials in DWIA inelastic scattering calculations is shown by some examples. 相似文献
9.
Analyzing powers measured in the study of bombarding energy show strong J-dependence and have been used to clearly assign the spin of a number of low-lying states in the residual nucleus. At high excitation energy (3.5–6 MeV). the inner-hole strength is shared between clearly isolated peaks on one hand and a fragmented structure on the other. This work reports on the determination of the spin of the inner-hole states and consequently on a more precise measurement of the overlapping regions between Subshell components. The analyzing power data shows that the group of peaks located between 3.4 and 4.5 MeV consist of spins , in agreement with the excitation of the inner- hole strengths in 111Sn. In addition a substantial amount of the component is observed between 4.5 and 6.0 MeV.The results of the data analysis allow us to clearly eastablish the spreading of the innerhole strength and to a lesser extent the strong fragmentation of the inner-hole subshells. 相似文献
10.
High resolution laser Stark excitation of np (60相似文献