J. Hitchcock

Phase coherence and superfluid-insulator transition in a disordered Bose-Einstein condensate

We have studied the effects of a disordered optical potential on the transport and phase coherence of a Bose-Einstein condensate (BEC) of

Detecting antiferromagnetism of atoms in an optical lattice via optical Bragg scattering

^{7}\text{L}\text{i}

Photoassociation of a Bose-Einstein Condensate near a Feshbach Resonance

atoms. At moderate disorder strengths

All-optical production of a lithium quantum gas using narrow-line laser cooling

({V}_{D})

Dissipative transport of a Bose-Einstein condensate

, we observe inhibited transport and damping of dipole excitations, while in time-of-flight images, random but reproducible interference patterns are observed. In situ images reveal that the appearance of interference is correlated with density modulation, without complete fragmentation. At higher

Experimental studies of Bose–Einstein condensates in disorder

{V}_{D}

Progress toward realization of antiferromagnetic ordering of cold atoms in an optical lattice

, the interference contrast diminishes as the BEC fragments into multiple pieces with little phase coherence.

Demonstration of a

Antiferromagnetism of ultracold fermions in an optical lattice can be detected by Bragg diffraction of light, in analogy to the diffraction of neutrons from solid-state materials. A finite sublattice magnetization will lead to a Bragg peak from the ((1/2)(1/2)(1/2)) crystal plane with an intensity depending on details of the atomic states, the frequency and polarization of the probe beam, the direction and magnitude of the sublattice magnetization, and the finite optical density of the sample. Accounting for these effects we make quantitative predictions about the scattering intensity and find that with experimentally feasible parameters the signal can be readily measured with a CCD camera or a photodiode and used to detect antiferromagnetic order.

^{6}

We measure the effect of a magnetic Feshbach resonance (FR) on the rate and light-induced frequency shift of a photoassociation resonance in ultracold 7Li. The photoassociation-induced loss-rate coefficient K_{p} depends strongly on magnetic field, varying by more than a factor of 10;{4} for fields near the FR. At sufficiently high laser intensities, K_{p} for a thermal gas decreases with increasing intensity, while saturation is observed for the first time in a Bose-Einstein condensate. The frequency shift is also strongly field dependent and exhibits an anomalous blueshift for fields just below the FR.

Li magneto-optical trap using the

We have used the narrow 2S{sub 1/2}{yields}3P{sub 3/2} transition in the ultraviolet (uv) to laser cool and magneto-optically trap (MOT) {sup 6}Li atoms. Laser cooling of lithium is usually performed on the 2S{sub 1/2}{yields}2P{sub 3/2} (D2) transition, and temperatures of {approx}300 {mu}K are typically achieved. The linewidth of the uv transition is seven times narrower than the D2 line, resulting in lower laser cooling temperatures. We demonstrate that a MOT operating on the uv transition reaches temperatures as low as 59 {mu}K. Furthermore, we find that the light shift of the uv transition in an optical dipole trap at 1070 nm is small and blueshifted, facilitating efficient loading from the uv MOT. Evaporative cooling of a two spin-state mixture of {sup 6}Li in the optical trap produces a quantum degenerate Fermi gas with 3x10{sup 6} atoms in a total cycle time of only 11 s.