Dual-species quantum degeneracy of potassium-40 and rubidium-87 on an atom chip

In this article we review our recent experiments with a 40K-87Rb mixture. We demonstrate rapid sympathetic cooling of a 40K-87Rb mixture to dual quantum degeneracy on an atom chip. We also provide details on efficient BEC production, species-selective magnetic confinement, and progress toward integration of an optical lattice with an atom chip. The efficiency of our evaporation allows us to reach dual degeneracy after just 6 s of evaporation - more rapidly than in conventional magnetic traps. When optimizing evaporative cooling for efficient evaporation of 87Rb alone we achieve BEC after just 4 s of evaporation and an 8 s total cycle time.Comment: 8 pages, 4 figures. To be published in the Proceedings of the 20th International Conference on Atomic Physics, 2006 (Innsbruck, Austria

Phase Space Tomography of Classical and Nonclassical Vibrational States of Atoms in an Optical Lattice

Atoms trapped in optical lattice have long been a system of interest in the AMO community, and in recent years much study has been devoted to both short- and long-range coherence in this system, as well as to its possible applications to quantum information processing. Here we demonstrate for the first time complete determination of the quantum phase space distributions for an ensemble of $^{85}Rb$ atoms in such a lattice, including a negative Wigner function for atoms in an inverted state.Comment: Submitted to Journal of Optics B: Quantum and Semiclassical Optics. Special issue in connection with the 9th International Conference on Squeezed States and Uncertainty Relations, to be held in Besancon, France, on 2-6 May 200

Comment on ``Manipulating the frequency entangled states by an acoutic-optical modulator''

A recent theoretical paper [1] proposes a scheme for entanglement swapping utilizing acousto-optic modulators without requiring a Bell-state measurement. In this comment, we show that the proposal is flawed and no entanglement swapping can occur without measurement.Comment: 6 pages, 2 figures submitted to Phys. Rev

Rapid sympathetic cooling to Fermi degeneracy on a chip

Neutral fermions present new opportunities for testing many-body condensed matter systems, realizing precision atom interferometry, producing ultra-cold molecules, and investigating fundamental forces. However, since their first observation, quantum degenerate Fermi gases (DFGs) have continued to be challenging to produce, and have been realized in only a handful of laboratories. In this Letter, we report the production of a DFG using a simple apparatus based on a microfabricated magnetic trap. Similar approaches applied to Bose-Einstein Condensation (BEC) of 87Rb have accelerated evaporative cooling and eliminated the need for multiple vacuum chambers. We demonstrate sympathetic cooling for the first time in a microtrap, and cool 40K to Fermi degeneracy in just six seconds -- faster than has been possible in conventional magnetic traps. To understand our sympathetic cooling trajectory, we measure the temperature dependence of the 40K-87Rb cross-section and observe its Ramsauer-Townsend reduction.Comment: 5 pages, 4 figures (v3: new collision data, improved atom number calibration, revised text, improved figures.

Comment on ''Manipulating the frequency-entangled states by an acoustic-optical modulator''

A recent theoretical paper by Shi et al. ͓Phys. Rev. A 61, 064102 ͑2000͔͒ proposes a scheme for entanglement swapping utilizing acousto-optic modulators without requiring a Bell-state measurement. In this Comment, we show that the proposal is flawed and no entanglement swapping can occur without measurement