Diffraction-limited focusing of Bose–Einstein condensates

Abstract

We report adjustable magnetic `bouncing' and focusing of a dilute $^{87}$Rb\nBose gas. Both the condensate production and manipulation are realised using a\nparticularly straight-forward apparatus. The bouncing region is comprised of\napproximately concentric ellipsoidal magnetic equipotentials with a centre that\ncan be adjusted vertically. We extend, and discuss the limitations of, simple\nThomas-Fermi and Monte-Carlo theoretical models for the bouncing, which at\npresent find close agreement with the condensate's evolution. Very strong\nfocusing has been inferred and the observation of atomic matter-wave\ndiffraction should be possible. Prospects look bright for applications in\nmatter-wave atom-optics, due to the very smooth nature of the mirror.\n