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

从宇称和时间反转对称性破坏等基础研究到光学频率标准等应用，Yb原子引起了人们的极大关注。我们对玻色-爱因斯坦凝聚(BEC)等量子简并气体和Yb原子稀薄原子气体的费米简并进行了实验研究，通过优化高密度光陷和蒸发冷却，实现了174Yb BEC的稳定形成。通过共振冷却，176Yb的相空间密度大于1，实现了Yb费米子同位素(^&lt；171&gt；Yb，^&lt；173&gt；Yb)的费米简并。为了克服相同费米子之间弹性碰撞的抑制，我们在171Yb冷却的情况下成功地应用了波色子同位素174Yb的共生冷却，在173Yb的情况下成功地对6个自旋混合物进行了蒸发冷却，导致了费米温度以下的冷却。此外，我们还成功地利用相互结合线进行了高分辨率的光缔合光谱，获得了关于174Yb的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.