Demonstration of a $^{6}$Li magneto-optical trap using the $2S_{1/2}\rightarrow 3P_{3/2}$ transition

ORAL

Abstract

We demonstrate narrow linewidth laser cooling on the $2S_{1/2}\rightarrow 3P_{3/2}$ transition of $^{6}$Li at 323 nm. Typically, magneto-optical traps (MOTs) of alkali atoms cool on the D2 transition. The linewidth of this transition determines the Doppler limit of cooling which in the case of $^{6}$Li is 140 $\mu$K, given a 5.9 MHz transition linewidth. Due to a lack of resolved hyperfine structure that prohibits polarization gradient cooling, typical Li MOTs reach minimum temperatures near 300 $\mu$K. Cooling on the $2S_{1/2}\rightarrow 3P_{3/2}$ transition, however, allows for a Doppler limit of 20 $\mu$K since the transition linewidth is only 790 kHz. We have implemented this cooling scheme and demonstrate $^{6}$Li MOT temperatures of 65 $\mu$K. With the increased phase space density from this MOT, initial loading of the gas to an optical trap is substantially enhanced. We present our results on the characteristics of the narrow linewidth MOT and our results on the benefits of using this cooling scheme in the preparation of a degenerate gas of fermions.

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Authors

  • R. Hart

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005

  • P.M. Duarte

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Rice University, Department of Physics and Astronomy, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005

  • T.L. Yang

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005

  • J.M. Hitchcock

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005

  • T.A. Corcovilos

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005

  • R.G. Hulet

    Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Rice University, Department of Physics and Astronomy, Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, TX 77005