Berlin 2001 – scientific programme

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AMPD: EPS AMPD

AMPD 6: Sitzung 6

AMPD 6.5: Talk

Wednesday, April 4, 2001, 11:20–11:45, H104

Asymptotic models for interpretation of ultracold molecule spectroscopy experiments — •Anne Crubellier, Benoît T’Jampens, Bruno Laburthe Tolra, Cyril Drag, Daniel Comparat, and Pierre Pillet — Laboratoire Aimé Cotton, CNRS, bât. 505, Campus d’Orsay, F-91405 Orsay Cedex, France

In experiments with ultracold atoms and molecules, atomic interaction often operates at large distances, in the so–called asymptotic region. In addition, the inner part of the interaction potential, whose knowledge is essential in usual treatments, is generally not known with enough precision to be actually usable. Numerous methods have been developed to deal efficiently with this situation. We have preferred a purely asymptotic method: inner part of the potentials is merely ignored and computation is performed in the external zone only.

Such asymptotic models have been used in the analysis of photoassociation spectra corresponding to molecular potential wells located at large distances [1,2], and also to derive a value of the triplet scattering length of cesium from photoassociation spectroscopy experiments [3].

A purely asymptotic method for the determination of scattering lengths using observed bound levels at the 3s + 3s asymptote of Na₂ has also been developed [4]. The basic point is the use of nodal lines, i.e. of lines connecting nodes of successive wavefunctions. The method has now been extended to multichannel case. Application to the analysis of bound levels of the ground states of Cs₂, recently measured in our group by two–color spectroscopy, will be described.

[1] D. Comparat, C. Drag, B. Laburthe Tolra, A. Fioretti, P. Pillet, A. Crubellier, O. Dulieu, F. Masnou-Seeuws, Eur. Phys. J. D 11, 59 (2000).

[2] C. Drag, B. Laburthe Tolra, O. Dulieu, D. Comparat, M. Vatasescu, S. Boussen, S. Guibal, A. Crubellier, P. Pillet, IEEE Journal of Quantum Electronics on "Laser Cooling of Atoms and Molecules and its Applications" (2000).

[3] C. Drag, B. Laburthe Tolra, B. T’Jampens, D. Comparat, M. Allegrini, A. Crubellier, P. Pillet, Phys. Rev. Lett. 85, 1408 (2000).

[4] A. Crubellier, O. Dulieu, F. Masnou-Seeuws, M. Elbs, H. Knöckel, E. Tiemann, Eur. Phys. J. D 6, 211 (1999).