Laser cooling and dynamics of nanofiber-coupled atoms

Recently, a new experimental platform for the simultaneous trapping and optical interfacing of laser-cooled cesium atoms has been experimentally demonstrated in the group of Prof. Arno Rauschenbeutel at the Institute of Atomic and Subatomic Physics in Vienna. The scheme uses a two color evanescent field surrounding an optical nanofiber to localize the atoms in a one-dimensional optical lattice or in a one-dimensional guide for matter waves about 200 nm above the nanofiber surface. At the same time, the atoms can be efficiently interrogated with light which is sent through the nanofiber. In this context, the goal of the proposed project is to establish a consistent theoretical basis to describe laser cooling of nanofiber-coupled atoms to subrecoil temperatures and to outline possible applications of the linear and non-linear dynamics of the atoms in fundamental research and in quantum technologies. On the one hand, this description will enable, jointly with Prof. Rauschenbeutel`s group, to plan and to perform advanced experiments with nanofiber-coupled atoms and to quantitatively interpret their results. On the other hand, we expect also new insights and understanding with respect to interaction of atoms with light in low dimensions. These results will have their own theoretical significance and be of international interest.

Several thousands of atoms, laser radiation of moderate intensity can anything new be found in such a system? The answer is yes. We demonstrate theoretically that interactions between atoms placed near a specially designed one-dimensional structure can be strongly enhanced due to the modified vacuum of the electromagnetic modes near this structure. This modifies in turn the light propagation in the atomic medium. Our results can be applied in studies of fundamental problems of statistical physics, e.g., of systems with non-conventional, non-additive thermodynamic properties, or in quantum information processing.