Quantum optical interactions in trapped degenerate atomic gases

John E. Thomas

Jianping Yin

G. Edward Marti, Ryan Olf, Sean Lourette +1 more

Xiangchuan Yan, Da-Li Sun, Lu Wang +3 more

We report the experimental production of degenerate Fermi gases of 6Li atoms in an optical dipole trap. The gray-molasses technique is carried out to decrease the atomic temperature to 57 μK, which facilitates the efficient loading of cold atoms into the optical dipole trap. The Fermi degeneracy is achieved by evaporative cooling of a two-spin mixture of 6Li atoms on the Feshbach resonance. The degenerate atom number per spin is 3.5 × 104, and the reduced temperature T/T F is as low as 0.1, where T F is the Fermi temperature of the non-interacting Fermi gas. We also observe the anisotropic expansion of the atom cloud in the strongly interacting regime.

Daniel Schaeder Barker

We describe the construction and characterization of a new apparatus that can produce degenerate quantum gases of strontium. The realization of degenerate gases is an important first step toward future studies of quantum magnetism. Three of the four stable isotopes of strontium have been cooled into the degenerate regime. The experiment can make nearly pure Bose-Einstein condensates containing approximately 1x10^4 atoms, for strontium-86, and approximately 4x10^5 atoms, for strontium-84. We have also created degenerate Fermi gases of strontium-87 with a reduced temperature, T/T_F of approximately 0.2. The apparatus will be able to produce Bose-Einstein condensates of strontium-88 with straightforward modifications. We also report the first experimental and theoretical results from the strontium project. We have developed a technique to accelerate the continuous loading of strontium atoms into a magnetic trap. By applying a laser addressing the 3P1 to 3S1 transition in our magneto-optical trap, the rate at which atoms populate the magnetically-trapped 3P2 state can be increased by up to 65%. Quantum degenerate gases of atoms in the metastable 3P0 and 3P2 states are a promising platform for quantum simulation of systems with long-range interactions. We have performed an initial numerical study of a method to transfer the ground state degenerate gases that we can currently produce into one of the metastable states via a three-photon transition. Numerical simulations of the Optical Bloch equations governing the three-photon transition indicate that >90% of a ground state degenerate gas can be transferred into a metastable state.

Nathan Gemelke