Atomic Physics Seminars

Atomic clocks realize the most accurate measurements of any kind and are extremely sensitive to incredibly small perturbations. The current generation of atomic clocks uses laser-cooling and, after circumventing some new problems, these will realize 100 fold improvements in clock accuracies. I will describe the basic physics of clocks, the motivations for building better clocks, and several of the new problems. The new problems include frequency shifts due to collisions of the cold atoms, the size of the recoil of an atom when it absorbs a photon, and juggling many atoms in fountains. Looking forward, the next generation of atomic clocks will utilize optical frequency transitions. I will describe this elegant technology that allows us to count at optical frequencies (1015 Hz).