Role of wire imperfections in micromagnetic traps for atoms

Abstract

We present a quantitative study of roughness in the magnitude of the magnetic field produced by a current carrying microwire, i.e., in the trapping potential for paramagnetic atoms. We show that this potential roughness arises from deviations in the wire current flow due to geometric fluctuations of the edges of the wire: a measurement of the potential using cold trapped atoms agrees with the potential computed from the measurement of the wire edge roughness by a scanning electron microscope.