Properties of single atoms in a dipole trap

Summary form only given. Elementary quantum gate operations can be realized with two or more neutral atoms coupled to the mode of a high finesse optical cavity. However, this has not been achieved yet due to the lack of control of the exact number and position of the atoms. Our goal is to place a prescribed number of cold atoms into the resonator using an optical dipole trap. Single atoms have already been successfully transferred from a magneto-optical trap into a dipole trap, and a standing wave dipole trap has been used to transport atoms over macroscopic distances. Further cooling of the atoms in the dipole trap is imperative for complete control of their coupling to a cavity field, since residual motion disturbs the system. Atomic states are shifted due to the dipole trap laser (AC Stark effect) proportional to the laser intensity at the atom´s position. We use Raman sideband cooling along the axis of the standing wave dipole trap. The high axial oscillation frequency of 330 kHz allows the resolution of vibrational sidebands in Raman transitions between the hyperfine ground states of the cesium atoms. The final temperature is determined by Raman spectroscopy. Additionally we study heating induced by phase fluctuations of the dipole trapping laser beams, and directly measure the light shift of the Cs D2-transition by laser spectroscopy in the dipole trap.