Magnetic conveyor belt for transporting and merging trapped atom clouds

We demonstrate an integrated magnetic device which transports cold atoms ne ar a surface with very high positioning accuracy. Time-dependent currents i n a lithographic conductor pattern create a moving chain of potential wells ; atoms are transported in these wells while remaining confined in all thre e dimensions. We achieve mean fluxes up to 10(6) s(-1) with a negligible he ating rate. An extension of this device allows merging of atom clouds by un ification of two Ioffe-Pritchard potentials. The unification, which we demo nstrate experimentally, can be performed without loss of phase space densit y. This novel all-magnetic atom manipulation offers exciting perspectives, such as trapped-atom interferometry.