Manipulating and measuring single atoms in the Maltese cross geometry

Abstract

We describe optical methods for trapping, cooling, and observing single 87 Rb atoms in a four-lens "Maltese cross" geometry (MCG). The use of four high numerical-aperture lenses in the cardinal directions enables efficient collection of light from non-collinear directions, but also restricts the optical access for cooling and optical pumping tasks. We demonstrate three-dimensional atom localization with sub-wavelength precision, and present measurements of the trap lifetime, temperature and transverse trap frequency in this geometry. We observe a trap performance comparable to what has been reported for single-atom traps with one-or two-lens optical systems, and conclude that the additional coupling directions provided by the MCG come at little cost to other trap characteristics.

Dipole-dipole Interactions Through a Lens

“…Technological advances in the last decade have facilitated the probing and control of single atoms by collecting and focusing light with the help of high numerical aperture (NA) lenses. Some example of this progress are quantum gas microscopes [1][2][3][4][5], programmable atom arrays [6][7][8], and other novel arrangements of lenses to improve atom-field interfaces [9,10]. State-of-the-art optical elements allow for an NA as high as 0.92 [11], near the theoretical limit.…”