Suppression of Ultracold Ground-State Hyperfine-Changing Collisions with Laser Light

Abstract

Using laser light tuned to a repulsive molecular potential, we have been able to suppress inelastic ground-state hyperfine-changing collisions between ultracold R b atoms. Adiabatic excitation to the repulsive curve alters the atomic trajectories and prevents the atoms from approaching close enough for the hyperfine change to occur. Experimental results show suppressions up to -50% and are in reasonable agreement with a simple Landau-Zener model. Our ability to control collisional trap loss processes may have important implications for the achievement of high densities in laser cooled samples.

Formation of ultracold Rb2 molecules in the v′′ = 0 level of the a3Σ+u state via blue-detuned photoassociation to the 13Πg state

“…However an estimate based on ref. 10 indicates that these effects should be negligibly small for our experimental configuration. Here, we demonstrate blue-detuned photoassociation to the short-range 1 3 P g state of 85 Rb 2 as shown in Fig.…”

Photoassociation of Ultracold Atoms: A New Spectroscopic Technique

“…We also note that photoassociative spectroscopy may be useful as a probe of the short-range approach of cold atoms. Such a probe may also allow more detailed studies of optical "shielding" of collisions (3,(171)(172)(173)(174), where close approach is suppressed by excitation to a repulsive potential.…”

Influence of Nearly Resonant Light on the Scattering Length in Low-Temperature Atomic Gases

“…As the interaction between atoms in the excited state is much stronger than in the ground state, at moderate light intensities the scattering amplitude can already be significantly changed. Aside from the collective effects, as discussed here, optical control of the rates of intrinsic inelastic collisions [6,12] and elastic collisional rates [13] has attracted a lot of interest.…”