Two- and three-dimensional atomic crystals bound by light

Theodor W. Hänsch

Graham P. Collins

Researchers in Germany and France have bound neutral atoms in regular two- and three-dimensional lattices induced by the interference patterns of several laser beams. The work builds on the techniques of magnetooptical trapping and sub-Doppler laser cooling and on previous work in which atoms were bound in onedimensional standing waves of light. The fields of light in these techniques are called optical molasses, because atoms within them experience viscous forces, which cool the atoms to temperatures on the order of microkelvins. In the new, “crystalline” molasses, the standing waves produce a stable, regular array of potential wells—a microscopic “egg carton”— and the atoms become localized at the bottoms of the wells.

André LeClair

We solve for the exact atom-field eigenstates of a single atom in a three dimensional spherical cavity, by mapping the problem onto the anisotropic Kondo model. The spectrum has a rich bound state structure in comparison with models where the rotating wave approximation is made. It is shown how to obtain the Jaynes-Cummings model states in the limit of weak coupling. Non-perturbative Lamb shifts and decay rates are computed. The massive Kondo model is introduced to model light localization in the form of photon-atom bound states in photonic crystals.

Andreas Hemmerich, Theodor W. Hänsch

André LeClair

We give a particle description of atom–field eigenstates in a three-dimensional spherical geometry of infinite volume by mapping the problem onto the anisotropic Kondo model. The spectrum has a rich bound state structure in comparison with models where the rotating wave approximation is made. It is shown how to obtain the Jaynes–Cummings model states in the limit of weak coupling. Nonperturbative Lamb shifts and decay rates are computed. The massive Kondo model is introduced to model light localization in the form of photon–atom bound states in photonic crystals.

Helmut Ritsch