Cooling Dynamics in Optical Lattices

S. L. Rolston, Georg A. Raithel, G. Birki +2 more

Ivan Deutsch, J. Grondalski, Paul M. Alsing

Using the basis of Wannier states, we study the local dynamics of polarization gradient cooling for an atom driven on a ${J}_{g}=2\ensuremath{\rightarrow}{J}_{e}=3$ transition by a one-dimensional optical lattice. This analysis allows us to formulate a physical picture of the cooling mechanism, analogous to Sisyphus cooling for a ${J}_{g}=1/2\ensuremath{\rightarrow}{J}_{e}=3/2$ atom, which depends strongly on coherences in the Zeeman sublevels of the ground state. In addition, we are able to explain the steady-state properties of the laser-cooled atoms in a regime where the standard semiclassical analysis breaks down.

Jyrki Piilo, Kalle‐Antti Suominen, Kirstine Berg‐Sørensen

We have simulated the dynamics of interacting atoms in optical lattices. The periodic lattice structure is produced with laser beams detuned a few linewidths to the red from the atomic transition. The atoms localize in lattice sites as a steady state is reached during the cooling, but they can still to some extent move between the sites. Our Monte Carlo Wave Function simulations show that in such situations the interactions can lead to evaporative cooling of the atoms as the hotter ones are ejected from the lattice.

Laurent Sanchez-Palencia, G. Grynberg

Jyrki Piilo, Kalle‐Antti Suominen, Kirstine Berg‐Sørensen

We simulate collisions between two atoms, which move in an optical lattice under the dipole-dipole interaction. The model describes simultaneously the two basic dynamical processes, namely the Sisyphus cooling of single atoms, and the light-induced inelastic collisions between them. We consider the $J=1/\stackrel{\ensuremath{\rightarrow}}{2}J=3/2$ laser cooling transition for Cs and Na. We find that the hotter atoms in a thermal sample are selectively lost or heated by the collisions, which modifies the steady-state distribution of atomic velocities, reminiscent of the evaporative cooling process.

Michael J. Gibbons, Peyman Ahmadi, Kevin Fortier +2 more