Spatially selective loading of an optical lattice by light-shift engineering using an auxiliary laser field

We report on a method of light-shift engineering where an auxiliary laser is used to tune the atomic transition frequency. The technique is used to selectively load a specific region of an optical lattice. The results are explained by calculating the differential light-shift of each hyperfine state. We conclude that the remarkable spatial selectivity of light-shift engineering using an auxiliary laser provides a powerful technique to prepare ultra-cold trapped atoms for experiments on quantum gases and quantum information processing.