Designing potentials by sculpturing wires
  Magnetic trapping potentials for atoms on atom chips are determined by the current flow in the chip wires. By modifying the shape of the conductor we can realize specialized current flow patterns and therefore micro-design the trapping potentials. We have demonstrated this by nano-machining an atom chip using the focused ion beam technique. We built a trap, a barrier and using a BEC as a probe we showed that by polishing the conductor edge the potential roughness on the selected wire can be reduced. Furthermore we give different other designs and discuss the creation of a 1D magnetic lattice on an atom chip. 
Leonardo Della Pietra, Simon Aigner, Christoph vom Hagen, S\"onke   Groth, Israel Bar-Joseph, Henri J.Lezec, J\"org Schmiedmayer