Ultracold Strontium

锶最近已经成为研究激光冷却、光学频率标准、冷碰撞和量子简并气体的实验和理论原子物理小组紧张工作的焦点。这项实验研究计划侧重于确定碰撞性质和基态势，这些性质和基态势将构成锶应用继续取得进展的基础，例如用于优化蒸发冷却或碰撞时钟偏移的散射长度，或与原子结构计算相比较的长程势参数。第一个实验将是双原子锶分子基态电势最高能级的双色光缔合光谱。随后的实验将利用所学到的信息来探索光学诱导的费什巴赫共振，并创造量子简并气体。锶玻色-爱因斯坦凝聚不会简单地证明另一个凝聚原子。光学诱导的Feshbach共振将允许在比磁性Feshbach共振更快的时间尺度或更精细的空间尺度上灵活地操纵原子-原子相互作用。玻色同位素中缺乏超精细结构可能使凝聚态对环境扰动不敏感，更适合于原子光学和干涉应用。该项目的更广泛影响涉及到对学生的教育以及在多样性方面的努力。

Strontium has recently become the focus of intense work by experimental and theoretical atomic physics groups studying laser cooling, optical frequency standards, cold collisions, and quantum degenerate gases. This experimental research program focuses on determining collisional properties and ground state potentials that will form the foundation for continued progress in the application of strontium, such as scattering lengths for optimizing evaporative cooling or collisional clock shifts, or long range potential parameters to compare with atomic structure calculations. The first experiments will be two-color photoassociative spectroscopy of the highest-lying levels of the diatomic strontium molecular ground-state potential. Later experiments will take advantage of the information learned to explore optically induced Feshbach resonances and create quantum degenerate gases. Strontium Bose-Einstein condensation will not simply demonstrate another condensed atom. Optically induced Feshbach resonances will allow flexible manipulation of atom-atom interactions on a more rapid time scale or finer spatial scale than is possible with magnetic Feshbach resonances. The lack of hyperfine structure in bosonic isotopes may make condensates insensitive to environmental perturbations and better suited for atom-optic and interferometric applications. The broader impact of the program involves education of students as well as efforts in diversity.