Tuning the scattering length on the ground triplet state of Cs-2

Two schemes for tuning the scattering length on the ground triplet state of Cs-2 are developed. The absolute value of the triplet scattering length of Cs-133(2) is determined from the experimental data [A. Fioretti, D. Compar at, C. Drag, C. Amiot, O. Dulieu, F. Masnou-Seeuws, and P. Pillet, Eur. Phy s. J. D 5, 389 (1999)], we demonstrate that the large scattering length can be made small and positive by coupling the (3)Sigma (+)(u)(6S+6S) potentia l to the (3)Pi (g) state by strong off-resonant radiation. A weaker laser f ield coupling the (3)Sigma (+)(u)(6S+6S) continuum to the lowest bound leve l of the excited (3)Sigma (+)(g)(6S+6P) state also leads to a small positiv e scattering length. The scattering length of the Cs-135 isotope is found t o be positive. The method used solves the Schrodinger equation for two elec tronic states coupled by an electromagnetic field with no approximations em ployed. The scattering length is determined from the calculated continuum w ave functions at low energies. (C) 2001 American Institute of Physics.