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

Abstract

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 2.4×10 5 G/cm and the field curvature greater than 4.05×10 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.