Bose–Einstein condensates in a ring optical lattices trap

Anand K. Ramanathan, Sérgio Ricardo Muniz, Kevin Wright +3 more

Ji-Guo Wang, Wei Wang, Xiaodong Bai +1 more

K Henderson, C Ryu, C MacCormick +1 more

There is a pressing need for robust and straightforward methods to create potentials for trapping Bose–Einstein condensates (BECs) that are simultaneously dynamic, fully arbitrary and sufficiently stable to not heat the ultracold gas. We show here how to accomplish these goals, using a rapidly moving laser beam that 'paints' a time-averaged optical dipole potential in which we create BECs in a variety of geometries, including toroids, ring lattices and square lattices. Matter wave interference patterns confirm that the trapped gas is a condensate. As a simple illustration of dynamics, we show that the technique can transform a toroidal condensate into a ring lattice and back into a toroid. The technique is general and should work with any sufficiently polarizable low-energy particles.

Antoine Browaeys, J. V. Porto, S P. Peil +3 more

Daniel S. Goldbaum, Erich J. Mueller

We present a theoretical study of vortices within a harmonically trapped Bose-Einstein condensate in a rotating optical lattice. We find that proximity to the Mott insulating state dramatically affects the vortex structures. To illustrate, we give examples in which the vortices (i) all sit at a fixed distance from the center of the trap, forming a ring, or (ii) coalesce at the center of the trap, forming a giant vortex. We also model time-of-flight expansion.

O. Morsch