Demonstration and characterization of a 3D optical lattice

Summary form only given. A new type of double optical lattice is presented. This is two optical lattices, of practically the same spatial frequency, which can be translated independently of each other. The two lattices trap atoms in two different hyperfine structure ground state of Cs, with two different laser frequencies, separated by 9 GHz. We show that the relative spatial phase between the lattices is stable, and can be set arbitrarily in three dimensions. By measuring the temperature in steady-state for different relative spatial phases, we are able to map out the modulated light shift potential. The result fits perfectly with a calculation of the intensity pattern of the light field. When the relative displacement of the lattices is set to zero, one has effectively two harmonic oscillators, with an asymmetric coupling between them via a thermal reservoir. This is a system which is interesting in itself for fundamental studies, and it opens the possibility for a variant of Raman sideband cooling, where the "repumping" is inherent in the system, and which works for different internal states simultaneously. By translating the optical lattices fast, using electro-optic modulators, we can induce pain/vise controlled interactions. This can be used for photoassociation, studies of cold collisions or as an ingredient in quantum state manipulations. We have investigated the decoherence times, and the possibility to use this system for quantum state manipulation. It turns out that with proper choices of detunings and potential well depths, the double optical lattices is a promising candidate for realizing a quantum gate for neutral atoms.