Controllable Double-Well Magneto-Optical Trap for Neutral Atoms

We propose a novel controllable double-well magneto-optical trap (MOT) by using a square current-carrying wire and a bias magnetic field. The spatial distributions of the magnetic fields and their gradients are calculated, and the results show that the proposed trap has double magnetic wells with two centres of zero magnetic field and can be continuously evolved as a single-well trap by reducing the current in the wire or increasing the bias field, which can be used to realize a controllable double-well MOT, even to prepare one- and two-dimensional arrays of magneto-optical lattices on the surface of an atom chip. We also estimate the number (～10⁷) and temperature ( ～260μ K) of trapped cold atoms in our MOT.