Cavity QED and quantum-information processing with “hot” trapped atoms

We propose a method to implement cavity QED and quantum-information processing in high-Q cavities with a single trapped but nonlocalized atom. The system is beyond the Lamb-Dicke limit due to the atomic thermal motion. Our method is based on adiabatic passages, which make the relevant dynamics insensitive to the randomness of the atom position with an appropriate interaction configuration. The validity of this method is demonstrated from both approximate analytical calculations and exact numerical simulations. We also discuss various applications of this method based on the current experimental technology.