Formation, detection and spectroscopy of ultracold Rb2 in the ground X1Σg+ state
Formation, detection and spectroscopy of ultracold Rb2 in the ground X1Σg+ state
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X1Σg+ 基态超冷 Rb2 的形成、检测和光谱
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
W. Stwalley
中科院分区：
文献类型：
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作者：
Y. Huang;Jianbing Qi;H. Pechkis;Dajun Wang;E. Eyler;P. Gould;W. Stwalley
我们将磁光阱中的原子对光缔合成0 +态，形成超冷基态Rb2分子，0 +态辐射衰减为X1Σg+态的高振动能级。利用脉冲激光共振增强双光子电离，实现了灵敏的振动状态选择性检测。探测激光的频率扫描揭示了一个以前未观察到的电子激发态的长振动过程，我们将其确定为21Σu+状态。它的大部分振动谱与基于从头算势的预测非常一致，尽管最低的振动能级与三重态23Πu表现出强烈的扰动混合。本文报道的检测方法，除了细微的变化外，应该对X态的整个潜在井有效。在这项工作中，没有观察到高于v = 118的振动能级的跃迁，但这不是检测方法的限制，而是光缔合形成方案的限制，因为产生它们的同一光缔合激光器重新激发了最高v能级。
We form ultracold ground-state Rb2 molecules by photoassociating pairs of atoms in a magneto-optical trap into the 0u+ state, which decays radiatively into high vibrational levels of the X1Σg+ state. Sensitive and vibrationally state-selective detection is achieved by means of resonantly-enhanced two-photon ionization with a pulsed laser. Frequency scans of the detection laser reveal a long vibrational progression to a previously unobserved electronic excited state, which we identify as the 21Σu+ state. Most of its vibrational spectrum is in excellent agreement with predictions based on ab initio potentials, although the lowest vibrational levels exhibit strong perturbative mixing with the triplet 23Πu state. The detection method reported here, with minor variations, should be effective for the entire potential well of the X state. In this work no transitions are observed from vibrational levels above v = 118, but this turns out to be a limitation not of the detection method but rather of the photoassociative formation scheme, due to re-excitation of the highest-v levels by the same photoassociation laser that produces them.