Heteronuclear cold molecules laser spectroscopy

Abstract

Summary form only given. In order to characterize the K-Cs sample we performed trap loss measurements to evaluate the heteronuclear losses introduced by the overlapped samples one to each other. We present the heteronuclear loss rate observed on a cesium magneto-optical trap (MOT) due to collisions with the cold potassium atoms as a function of the Cs trap laser intensity. The result shows that the heteronuclear collisions are not likely to compromise the MOT number and density of trapped atoms. For the regular experimental conditions, very few heteronuclear molecules are expected to be produced. Therefore, to get better signal to noise ratio we decided to apply the pulsed ion production technique. Briefly, in the experiment there are two phases: trapping and probe. During the trap phase, the heteronuclear excited quasimolecules are photoassociated and during the probe phase they are photoionized by a laser pulse. The ions are collected by a channeltron and by the time-of-flight one may distinguish between the atomic and the molecular ions. The time diagram representing the experiment is shown. By scanning the frequency of the photoassociating probe laser, we shall be able to measure the bound states of the K-Cs molecule, and then to obtain the heteronuclear scattering length.