Anomalous longitudinal magnetic field near the surface of copper conductors

Abstract

We have used ultracold atoms to characterize the magnetic field near the\nsurface of copper conductors at room temperature carrying currents between\n0.045 A and 2 A. In addition to the usual circular field we find an additional,\n1000 - 10000 times smaller longitudinal field. The field changes its strength\nperiodically with a period of 200-300 um.\n