Single site addressability in optical lattices

Single site resolution in short-wavelength optical lattices, which have a significant tunnel coupling, is a challenging task. We prepare a BEC of rubidium atoms in a 3D lattice of 532 nm spacing. Using the 5S1/2 to 6P3/2 transition at 420nm, our imaging system (NA=0.7) will yield a resolution of 380nm and there-fore allow single site resolved detection and manipulation. So far we have taken in trap fluorescence images with a resolution of 700 nm using the 5S1/2 to 5P3/2 transition at 780nm and demonstrated the micro-manipulation of a few atoms with a tightly focused dipole trap. To extract one or a few slices and remove the atoms that are out of the depth of focus we use microwave transitions in a magnetic field gradient. The single site resolution will open up a new class of experiments in quantum simulation of strongly correlated systems - like the in-situ observation of the Mott insulator or the investigation of non-equilibrium phenomena - and in quantum information processing - like local spin manipulation or quantum gates with Rydberg atoms.