Magnetization and spin-flip dynamics of atoms in optical lattices

Abstract
We show, experimentally and using quantum Monte Carlo simulations, that the quasithermal paramagnetic behavior of cesium atoms in a one-dimensional linlin optical lattice is characterized by a spin temperature of twice the zero-field kinetic temperature. The magnetization is maximum and almost perfect when the Zeeman shift of the extreme magnetic sublevels approximately equals half the maximum light shift. The lifetime of magnetization and the laser-cooling time constant are found to be clearly distinct, the magnetization decay time amounting to at least three times the cooling time. Using simulations we find that the magnetic-dipole correlation time is approximately proportional to the angular momentum F of the atoms, while cooling and energy correlation time constants are approximately independent of F. Our results imply that for large F laser cooling within single light-shift potential wells (local cooling) occurs.