The authors review progress in understanding the nature of atomic collisions occurring at
temperatures ranging from the millidegrees Kelvin to the nanodegrees Kelvin regime. The …

We calculate the magnetic field and temperature dependence of the rates for all two-body
spin-exchange and dipolar transitions among hyperfine levels in cryogenic H gas by means …

We calculate rates for two exothermic excited-state collision processes involving sodium at
ultracold temperatures. We predict that the rate for fine-structure changing collisions …

We measure a cold collision frequency shift in an 87 Rb fountain clock that is fractionally 30
times smaller than that for Cs. The shift is− 0.38 (8) mHz for a density of 1.0 (6)× 10 9 cm− 3 …

We study theoretically the dimensional crossover from a three-dimensional elongated
condensate to a one-dimensional condensate as the transverse degrees of freedom get …

We have observed the cold collision frequency shift of the 1 S-2 S transition in trapped spin-
polarized atomic hydrogen. We find Δ ν 1 S− 2 S=− 3.8±0.8× 10− 10 n Hz cm 3, where n is …

We present the properties and advantages of a new magneto-optical trap (MOT) where blue-
detuned light drives “type-II” transitions that have dark ground states. Using Rb 87, we reach …

New experiments were proposed recently to investigate the regime of cold atomic and
molecular ion-atom collision processes in a special hybrid neutral-atom–ion trap under high …

One of the most well-developed applications of coherent interaction with atoms is atomic
frequency standards and clocks. Atomic clocks find significant roles in a number of scientific …

Using information from a recent 85 Rb two-color photoassociation experiment, we evaluate
the merits of fountain clocks based on 87 Rb and 85 Rb isotopes as alternatives to 133 Cs …