We propose two novel double-well magnetic surface traps (i.e., a double-well U-U-shaped wire trap and a double-well U-Z-shaped wire trap) for cold atoms using a straight and U-shaped current-carrying wire or two U-shaped current-carrying wires. These double-well magnetic traps can be continuously changed into a single-well by reducing the current in a straight wire or an inner U-shaped wire from a suitable value to zero, and vice versa. The spatial distributions of the magnetic fields from two current-carrying wire layouts and their field gradients are calculated and analyzed, and the trapped atomic number and its temperature in each magnetic well are estimated. Our study shows that our double-well magnetic surface traps can be used to realize two-species magneto-optical traps (MOTs) above the surface of the wire plane. Under the approximation of low intensity, cold atomic samples with a captured number of ∼10^6 atoms and a temperature of approximately 270 µK can be obtained in each ^85Rb atomic MOT. Since each MOT in two-species MOTs can be prepared independently, our controllable double-well trap can be used to study the cold collisions between two different atomic samples.
© 2005 Optical Society of America
(020.0020) Atomic and molecular physics : Atomic and molecular physics
(020.7010) Atomic and molecular physics : Laser trapping
(020.7490) Atomic and molecular physics : Zeeman effect
(230.3990) Optical devices : Micro-optical devices
Jianjun Hu, Jianping Yin, and Jianjun Hu, "Double-well surface magneto-optical traps for neutral atoms in a vapor cell," J. Opt. Soc. Am. B 22, 937-942 (2005)