Observation of the Efimov state of the helium trimer
Observation of the Efimov state of the helium trimer
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DOI：
10.1126/science.aaa5601
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发表时间：
2015-05-01
期刊：
影响因子：
56.9
通讯作者：
Doerner, Reinhard
中科院分区：
文献类型：
--
作者：
Kunitski, Maksim;Zeller, Stefan;Doerner, Reinhard
量子理论表明，当三体系统中的两体相互作用减弱时，在这些三体态释放之前，会出现无限数量的巨大空间范围的三体束缚态。据预测，三个氦（He）原子会形成一个分子系统，该系统在自然条件下表现出这种特性，而无需通过外部场人为调整粒子之间的吸引力。在这里，我们报告了通过库仑爆炸成像对 He-4(3) 这种长期预测但实验上难以捉摸的 Efimov 态的实验观察。我们展示了 Efimov 态的空间图像，确认了预测的大小和典型结构，其中两个原子彼此靠近，而第三个原子则远离。
Quantum theory dictates that upon weakening the two-body interaction in a three-body system, an infinite number of three-body bound states of a huge spatial extent emerge just before these three-body states become unbound. Three helium (He) atoms have been predicted to form a molecular system that manifests this peculiarity under natural conditions without artificial tuning of the attraction between particles by an external field. Here we report experimental observation of this long-predicted but experimentally elusive Efimov state of He-4(3) by means of Coulomb explosion imaging. We show spatial images of an Efimov state, confirming the predicted size and a typical structure where two atoms are close to each other while the third is far away.