We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magne...We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magnetic field is calibrated by measuring the Zeeman shift of the optical transition.A non-monotonic anisotropic expansion is observed across the Feshbach resonance.The density distribution is explored in different interacting regimes,where a condensate of diatomic molecules forms in the BEC limit with the indication of a bimodal distribution.We also measure the three-body recombination atom loss in the BEC-BCS crossover,and find that the magnetic field of the maximum atom loss is in the BEC limit and gets closer to the Feshbach resonance when decreasing the atom temperature,which agrees with previous experiments and theoretical prediction.This work builds up a controllable platform for the study on the strongly interacting Fermi gas.展开更多
We report the experimental production of degenerate Fermi gases of 6 Li atoms in an optical dipole trap.The gray-molasses technique is carried out to decrease the atomic temperature to 57 μK,which facilitates the eff...We report the experimental production of degenerate Fermi gases of 6 Li 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 ~6 Li atoms on the Feshbach resonance.The degenerate atom number per spin is 3.5×10^(4),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.展开更多
基金the National Key Research and Development Program of China(Grant No.2016YFA0301503)the National Natural Science Foundation of China(Grant Nos.11674358,11434015,and 11974384)+1 种基金Chinese Academy of Sciences(Grant No.YJKYYQ20170025)K.C.Wong Education Foundation(Grant No.GJTD-2019-15).
文摘We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magnetic field is calibrated by measuring the Zeeman shift of the optical transition.A non-monotonic anisotropic expansion is observed across the Feshbach resonance.The density distribution is explored in different interacting regimes,where a condensate of diatomic molecules forms in the BEC limit with the indication of a bimodal distribution.We also measure the three-body recombination atom loss in the BEC-BCS crossover,and find that the magnetic field of the maximum atom loss is in the BEC limit and gets closer to the Feshbach resonance when decreasing the atom temperature,which agrees with previous experiments and theoretical prediction.This work builds up a controllable platform for the study on the strongly interacting Fermi gas.
基金Supported by the National Key Research and Development Program of China (Grant No.2016YFA0301503)the National Natural Science Foundation of China (Grant Nos.11674358,11434015,and 11974384)+1 种基金the Chinese Academy of Sciences (Grant No.YJKYYQ20170025)K.C.Wong Education Foundation (Grant No.GJTD-2019-15)。
文摘We report the experimental production of degenerate Fermi gases of 6 Li 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 ~6 Li atoms on the Feshbach resonance.The degenerate atom number per spin is 3.5×10^(4),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.
