Realization of new quantum degenerate system of rare-earth Yb atoms and its new development

镱原子从宇称、时间反演对称性破坏等基础研究到光频标等应用，都引起了人们的广泛关注。我们对镱原子的玻色-爱因斯坦凝聚（BEC）和费米简并等量子简并气体进行了实验研究，通过优化高密度光阱和蒸发冷却实现了174 Yb BEC的稳定形成。通过共振冷却，我们获得了大于1的176 Yb的相空间密度，并实现了Yb费米同位素（~（40）Yb，~（40）Yb）的费米简并<171><173>。为了克服相同费米子之间弹性碰撞的抑制，我们成功地对171 Yb冷却采用玻色同位素174 Yb的共振冷却，对173 Yb冷却采用6自旋混合物的蒸发冷却，使其冷却到费米温度以下。此外，我们还成功地利用互组合线进行了高分辨率的光缔合光谱研究。获得了174 Yb散射长度的重要信息。

Ytterbium atoms attract much attention from fundamental research such as parity and time-reversal symmetry violation to the application such as optical frequency standard. We have studied experimentally quantum degenerate gases such as Bose-Einstein Condensation (BEC) and Fermi Degeneracy of dilute atomic gases of Ytterbium atoms.So far, we achieved stable formation of 174Yb BEC by optimizing high-density optical trapping and evaporative cooling. The number of atoms in BEC is increased by a factor of 10 to 50,000.We also obtained high phase space density more than 1 for 176Yb by sympathetic cooling.In addition, we realized Fermi Degeneracy of Yb fermionic isotopes (^<171>Yb,^<173>Yb). To overcome the suppression of elastic collision between identical fermions, we successfully applied sympathetic cooling with bosonic isotopes 174Yb in the case of 171Yb cooling and the evaporative cooling for the 6 spin mixtures in the case of 173Yb, which resulted in the cooling below Fermi temperature.In addition, we successfully performed high-resolution photoassociation spectroscopy using intercombination line, and obtained important information about scattering length of 174Yb.