Lab TourTrappingFalling This is the text for slide number one.

There have been various schemes for cooling and trapping neutral atoms with micron sized wires fabricated on a highly reflective surface. This kind of trap is capable of producing huge magnetic field gradients that can confine the atomic ensemble at a fixed distance from the chip - typically a few microns - hence the name "atom chip". The atom chip has various advantages over traditional magnetic traps. Some of the benefits include low-power consumption, higher gradients and trapping potentials, and precision small-scale control. There has been experimental progress in the development of possible quantum information devices, such as atom splitters and interferometers, and even guiding a BEC on a chip.

In progression toward a multiple component atom chip, we characterized the total loss rate for a two-species mirror magneto-optical trap (TSMMOT). The MMOT is the most commonly used tool for loading an atom chip. We measured the total loss rate for a cloud of ⁸⁵Rb (⁸⁷Rb) atoms that were immersed in a ¹³³Cs MOT. In a mixed trap, heteronuclear losses are the dominant mechanism. There is a dramatic increase in the total losses of Rb in the presence of Cs, whereas the Cs cloud is almost unperturbed by the presence of Rb. In addition, there is a isotopic difference in the heteronuclear loss rate between ⁸⁵Rb  and ⁸⁷Rb which is due to the difference in hyperfine structure energy levels between the isotopes. For more on these results please see our technical presentation.

In another experiment ultracold molecules have been produced by photoassociation of Cs atoms trapped in a mirror magneto-optical trap. The molecules were detected by resonantly enhanced multi-photon ionization followed by time-of-flight mass spectroscopy. The time-of-flight of atomic and molecular ions was investigated in the presence of a dc bias voltage applied to the conducting mirror. This technique provides a new tool for determining the distance between the cold molecules and the mirror surface. To view some of these most recent results, please click here.

We have also used an optical fiber based system to implement optical detection of atoms trapped on a reflective “atom-chip”. A fiber pair forms an emitter-detector setup that is bonded to the atom-chip surface to optically detect and probe laser cooled atoms trapped in a surface magneto-optical trap. We demonstrate the utility of this scheme by measuring the linewidth of the Cs D₂ line at different laser intensities.