Coherent micromanipulation of 1-D BEC in designed potentials

The manipulation of quantum degenerate gases has seen a flourishing of results in the last years. One of the most used tools to create and address a Bose-Einstein condensate (BEC) is the atomchip: A lithographycally patterned surface on which gold conductors are used to generate magnetic fields. To fully realize what the atomchip has to offer the miniaturization of structures and the integration of different devices (resonators, light fields, permanent magnets) are key factors. We have devised a method to micro-engineer the trapping potentials by sculpturing the chip, overcoming some limitations of the lithographic process. Numerical simulations are done on model cases to show the potentials they generate. Experimental data collected on one of these microstructured geometries confirms the expectations and gives indications on the quality of its magnetic potential. We propose also a periodic structure allowing to observe a quantum phase transition between a BEC and a Mott insulator. A further possibility for expanding the capabilities of the atomchip is integrating light fields close to its surface. We generate an optical lattice on our chip and use it to realize an atomic beamsplitter. Coherent splitting of a BEC is observed