Eur. Phys. J. D 65, 243-250 (2011)
https://doi.org/10.1140/epjd/e2011-20085-4

Regular Article

Optimal trapping wavelengths of Cs₂ molecules in an optical lattice

¹ Laboratoire Aimé Cotton, CNRS, Bât. 505, Université Paris-Sud, 91405 Orsay Cedex, France
² Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck Technikerstraße 25, 6020 Innsbruck, Austria

^a e-mail: olivier.dulieu@lac.u-psud.fr

Received: 31 January 2011
Received in final form: 23 April 2011
Published online: 4 August 2011

Abstract

The present paper aims at finding optimal parameters for trapping of Cs₂ molecules in optical lattices, with the perspective of creating a quantum degenerate gas of ground-state molecules. We have calculated dynamic polarizabilities of Cs₂ molecules subject to an oscillating electric field, using accurate potential curves and electronic transition dipole moments. We show that for some particular wavelengths of the optical lattice, called “magic wavelengths”, the polarizability of the ground-state molecules is equal to the one of a Feshbach molecule. As the creation of the sample of ground-state molecules relies on an adiabatic population transfer from weakly-bound molecules created on a Feshbach resonance, such a coincidence ensures that both the initial and final states are favorably trapped by the lattice light, allowing optimized transfer in agreement with the experimental observation.