Deterministic delivery of a single atom

We report the realization of a deterministic source of single atoms. A stan ding-wave dipole trap is Loaded with one or any desired number of cold cesi um atoms from a magneto-optical trap. By controlling the motion of the stan ding wave, we adiabatically transport the atom with submicrometer precision over macroscopic distances on the order of a centimeter. The displaced ato m is observed directly in the dipole trap by fluorescence detection. The tr apping field can also be accelerated to eject a single atom into free fligh t with well-defined velocities.