Physical Review A
Atomic vortex beams in focal regions
L. E. Helseth
Abstract
We discuss some classes of atomic lenses capable of generating atomic vortex beams. For certain lens classes one may associate a topological charge with the beam in the focal region, and it is shown that an energy of the order $\ensuremath{\Elzxh}/\ensuremath{\tau}$ is needed to alter the topological charge by $\ensuremath{\Delta}n=\ifmmode\pm\else\textpm\fi{}1,$ where $\ensuremath{\tau}$ is the atom interaction time with the lens. We also find that the vortex can be manipulated by the properties of the atomic lens. In particular, it is suggested that the circulation varies locally in space.