Sideband cooling of neutral atoms in a far-detuned optical lattice

Sideband laser cooling using stimulated Raman transitions is performed on trapped cesium atoms. The confinement is produced by a far–off-resonance dipole trap consisting of two crossed YAG beams which, by interference, create a one-dimensional optical lattice. In a pure intensity lattice, we measure a 1D temperature of T = 6 μK corresponding to a mean quantum vibrational number of about ⟨nv⟩ = 0.75. In a polarization gradient lattice, the final temperature is T = 3.6 μK corresponding to ⟨nv⟩ ≃ 2.4.