In a three-dimensional optical lattice for metastable xenon we observe the dynamical effects of the optical potential on Penning ionizing collisions between atoms. Enhancement of collisions over that for free atoms is observed at short times after the atoms are loaded into the lattice. After the atoms thermalize and localize into the potential wells, we observe a suppression of the collisions by as much as a factor of 2. From our measurements and a simple model we are able to extract an estimate of the rate at which atoms ``hop'' between wells.In a three-dimensional optical lattice for metastable xenon we observe the dynamical effects of the optical potential on Penning ionizing collisions between atoms. Enhancement of collisions over that for free atoms is observed at short times after the atoms are loaded into the lattice. After the atoms thermalize and localize into the potential wells, we observe a suppression of the collisions by as much as a factor of 2. From our measurements and a simple model we are able to extract an estimate of the rate at which atoms ``hop'' between wells.

Physical Review LettersJan 19, 199816 citations

Cold collisions in optical lattices

Jyrki Piilo

Työväentutkimus VuosikirjaJan 1, 20030 citations

New Experiments with Optical Lattices

A. Hemmericl, Axel Görlitz, Matthias Weidemüller +1 more

European Quantum Electronics Conference (EQEC)Jan 1, 19960 citations

Control of ultraslow inelastic collisions by Feshbach resonances and quasi-one- dimensional confinement

Vladimir Yurovsky, Y. B. Band

Inelastic collisions of ultracold atoms or molecules are analyzed using very general arguments. In free space, the deactivation rate can be enhanced or suppressed together with the scattering length of the corresponding elastic collision via a Feshbach resonance, and by interference of deactivation of the closed and open channels. In reduced dimensional geometries, the deactivation rate decreases with decreasing collision energy and does not increase with resonant elastic scattering length. This has broad implications; e.g., stabilization of molecules in a strongly confining two-dimensional optical lattice, since collisional decay of excited states due to inelastic collisions is suppressed. The relation of our results to the Lieb-Liniger model for bosonic atoms is addressed.Inelastic collisions of ultracold atoms or molecules are analyzed using very general arguments. In free space, the deactivation rate can be enhanced or suppressed together with the scattering length of the corresponding elastic collision via a Feshbach resonance, and by interference of deactivation of the closed and open channels. In reduced dimensional geometries, the deactivation rate decreases with decreasing collision energy and does not increase with resonant elastic scattering length. This has broad implications; e.g., stabilization of molecules in a strongly confining two-dimensional optical lattice, since collisional decay of excited states due to inelastic collisions is suppressed. The relation of our results to the Lieb-Liniger model for bosonic atoms is addressed.

arXiv:physics/0602181Physical Review AJan 23, 200713 citations

Electric field suppression of ultracold confined chemical reactions

Goulven Quéméner, John L. Bohn

We consider ultracold collisions of polar molecules confined in a one-dimensional optical lattice. Using a quantum scattering formalism and a frame transformation method, we calculate elastic and chemical quenching rate constants for fermionic molecules. Taking $^{40}\mathrm{K}$ $^{87}\mathrm{Rb}$ molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be $1$ s. We find a ratio of elastic to quenching collision rates of about $100$ , which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.We consider ultracold collisions of polar molecules confined in a one-dimensional optical lattice. Using a quantum scattering formalism and a frame transformation method, we calculate elastic and chemical quenching rate constants for fermionic molecules. Taking $^{40}\mathrm{K}$$^{87}\mathrm{Rb}$ molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be $1$ s. We find a ratio of elastic to quenching collision rates of about $100$, which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.

arXiv:1003.4026Physical Review AJun 9, 201066 citations

^{40}\mathrm{K}

^{87}\mathrm{Rb}

molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes for KRb molecules to be

1

s. We find a ratio of elastic to quenching collision rates of about

100

, which may be sufficient to achieve efficient evaporative cooling of polar KRb molecules.