Straight macroscopic magnetic guide for cold atom interferometer

We demonstrate a macroscopic magnetic guide for cold atom interferometry, where the magnetic guiding field is generated by a symmetrical array of racetrack coils of copper tape. This system represents a conceptual advance over previous guided atom interferometers based on nonsymmetrical geometries because the symmetry provides a much lower magnetic field curvature per fixed length than equivalent nonsymmetrical geometries, permitting a decrease in system length without increasing the decoherence rate associated with field curvature. We realized a magnetic guide a few cm away from each coil, where smooth translation of the guided atoms is achieved by changing the currents in second array of the multiple-conductor tape. (c) 2010 American Institute of Physics. [doi:10.1063/1.3506685]