FORMATION OF ULTRACOLD CESIUM MOLECULES IN THE GROUND ELECTRONIC STATE

We investigate theoretically the preparation of ultracold photoassociated Cs-2 molecules in the lowest vibrational level of the ground electronic state via the stimulated Raman adiabatic passage (STIRAP) by solving the time-dependent Schrodinger equation using the mapped Fourier grid method. A negative chirped laser pulse is used to produce the unstable photoassociated molecules in the excited electronic state. A dump pulse is utilized to transfer a partial population of the unstable photoassociated molecules to the vibrational v '' = 18 level of the ground electronic state. This part of population is then transferred to the v '' = 0 level of the ground electronic state by the pump and Stokes laser pulses via an intermediate state which is taken to be the v' = 7 level of the excited electronic state, forming the stable photoassociated molecules. The population transfer efficiency from v '' = 18 to v '' = 0 in the ground electronic state reaches 96.2% via the STIRAP.