We report a compact experimental setup for producing a quantum degenerate mixture of Bose23Na and Fermi40K gases. The atoms are collected in dual dark magneto–optical traps(MOT) with species timesharing loading to re...We report a compact experimental setup for producing a quantum degenerate mixture of Bose23Na and Fermi40K gases. The atoms are collected in dual dark magneto–optical traps(MOT) with species timesharing loading to reduce the light-induced loss, and then further cooled using the gray molasses technique on the D2line for23Na and D1line for40K. The microwave evaporation cooling is used to cool23Na in |F = 2, mF= 2〉 in an optically plugged magnetic trap, meanwhile,40K in |F = 9/2, mF= 9/2〉 is sympathetically cooled. Then the mixture is loaded into a large volume optical dipole trap where23Na atoms are immediately transferred to |1, 1〉 for further effective cooling to avoid the strong three-body loss between23Na atoms in |2, 2〉 and40K atoms in |9/2, 9/2〉. At the end of the evaporation in optical trap, a degenerate Fermi gas of40K with 1.9 × 10^(5) atoms at T/TF= 0.5 in the |9/2, 9/2〉 hyperfine state coexists with a Bose–Einstein condensate(BEC) of23Na with 8 × 10^(4) atoms in the |1, 1〉 hyperfine state at 300 n K. We also can produce the two species mixture with the tunable population imbalance by adjusting the 23Na magneto–optical trap loading time.展开更多
We report on the efficient gray molasses cooling of sodium atoms using the D2 optical transition at 589.1 nm.Thanks to the hyperfine split about 6Γ between |F’ = 2> and |F’ = 3> in the excited state 32 P3/2, ...We report on the efficient gray molasses cooling of sodium atoms using the D2 optical transition at 589.1 nm.Thanks to the hyperfine split about 6Γ between |F’ = 2> and |F’ = 3> in the excited state 32 P3/2, this atomic transition is effective for the gray molasses cooling mechanism. Using this cooling technique, the atomic sample in F = 2 ground manifold is cooled from 700 μK to 56 μK in 3.5 ms. We observe that the loading efficiency into magnetic trap is increased due to the lower temperature and high phase space density of atomic cloud after gray molasses. This technique offers a promising route for the fast cooling of the sodium atoms in the F = 2 state.展开更多
基金supported by the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0302003)the National Key Research and Development Program of China (Grant Nos. 2022YFA1404101, 2018YFA0307601,and 2021YFA1401700)+1 种基金the National Natural Science Foundation of China (Grant Nos. 12034011, 92065108, 11974224, 12022406, and 12004229)the Fund for Shanxi 1331 Project Key Subjects Construction。
文摘We report a compact experimental setup for producing a quantum degenerate mixture of Bose23Na and Fermi40K gases. The atoms are collected in dual dark magneto–optical traps(MOT) with species timesharing loading to reduce the light-induced loss, and then further cooled using the gray molasses technique on the D2line for23Na and D1line for40K. The microwave evaporation cooling is used to cool23Na in |F = 2, mF= 2〉 in an optically plugged magnetic trap, meanwhile,40K in |F = 9/2, mF= 9/2〉 is sympathetically cooled. Then the mixture is loaded into a large volume optical dipole trap where23Na atoms are immediately transferred to |1, 1〉 for further effective cooling to avoid the strong three-body loss between23Na atoms in |2, 2〉 and40K atoms in |9/2, 9/2〉. At the end of the evaporation in optical trap, a degenerate Fermi gas of40K with 1.9 × 10^(5) atoms at T/TF= 0.5 in the |9/2, 9/2〉 hyperfine state coexists with a Bose–Einstein condensate(BEC) of23Na with 8 × 10^(4) atoms in the |1, 1〉 hyperfine state at 300 n K. We also can produce the two species mixture with the tunable population imbalance by adjusting the 23Na magneto–optical trap loading time.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0301602the National Natural Science Foundation of China under Grant Nos 11474188 and 11704234+1 种基金the National Key Research and Development Program of China under Grant No 2018YFA0307601the Fund for Shanxi ‘1331 Project’ Key Subjects Construction,and the Program of Youth Sanjin Scholar
文摘We report on the efficient gray molasses cooling of sodium atoms using the D2 optical transition at 589.1 nm.Thanks to the hyperfine split about 6Γ between |F’ = 2> and |F’ = 3> in the excited state 32 P3/2, this atomic transition is effective for the gray molasses cooling mechanism. Using this cooling technique, the atomic sample in F = 2 ground manifold is cooled from 700 μK to 56 μK in 3.5 ms. We observe that the loading efficiency into magnetic trap is increased due to the lower temperature and high phase space density of atomic cloud after gray molasses. This technique offers a promising route for the fast cooling of the sodium atoms in the F = 2 state.
