Magnetic surface microtraps for realizing an array of alkali atomic Bose-Einstein condensates or Bose clusters

Single microscopic magnetic trap for neutral atoms using planar current-carrying wires was proposed and studied theoretically by Weinstein et al. [Phys. Rev. A, 52 (1995) 4004]. We propose one- and two-dimensional (1D and 2D) arrays of magnetic surface microtraps for cold alkali atoms using static magnetic fields, which are produced by some arrays of current-carrying wires. The spatial distributions of magnetic fields from 1D and 2D arrays of current-carrying wires are calculated, the field gradients and curvatures from a single magnetic microtrap are analyzed, and some interesting and periodic magnetic-well microstructures are found. We also discuss the experimental practicability and estimate the collision losses. Our study shows that the magnetic-field gradient greater than 2.4 x 10(5) G/cm and the field curvature greater than 4.05 x 10(8) G/cm(2) can be generated in our array of magnetic microtraps. which can be used to realize 1D and 2D arrays of Bose-Einstein condensations (or 1D and 2D arrays of Bose clusters) by rf-induced evaporative cooling, and then to form 1D and 2D atomic magnetic lattices. even to prepare 1D and 2D photonic crystals. (C) 2002 Published by Elsevier Science B.V.