Dynamic dipole polarizabilities of alkali dimers

Experiments aiming at trapping ultracold molecules and at manipulating their internal quantum state rely on their interaction with far-detuned laser fields. Using accurate potential energy curves and transition dipole moments from advanced quantum chemistry computations [1], we calculate the dynamic dipole polarizability of homonuclear and heteronuclear alkali dimers via a summation over a large number of excited electronic states. We identified ranges of ``magic'' wavelengths where the ac Stark shift for the dimer in its lowest vibrational level of the ground state is the same than for a pair of non-interacting atoms. We use the same formalism to evaluate dipole polarizabilities at imaginary frequencies which are relevant for computing long range interactions between atoms and molecules [2]. \\[4pt] [1] M. Aymar and O. Dulieu, Mol. Phys. \underline{105}, 1733 (2007)\\[0pt] [2] A. Derevianko , S. G. Porsev, and J. F. Babb, arXiv:0902.3929v1 [physics.atom-ph] 23 Feb 2009