Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany.
Department of Physics and Astronomy, Aarhus University, DK 8000 Aarhus C, Denmark.
Science. 2019 May 17;364(6441):664-667. doi: 10.1126/science.aaw4150.
The subnanoscale size of typical diatomic molecules hinders direct optical access to their constituents. Rydberg macrodimers-bound states of two highly excited Rydberg atoms-feature interatomic distances easily exceeding optical wavelengths. We report the direct microscopic observation and detailed characterization of such molecules in a gas of ultracold rubidium atoms in an optical lattice. The bond length of about 0.7 micrometers, comparable to the size of small bacteria, matches the diagonal distance of the lattice. By exciting pairs in the initial two-dimensional atom array, we resolved more than 50 vibrational resonances. Using our spatially resolved detection, we observed the macrodimers by correlated atom loss and demonstrated control of the molecular alignment by the choice of the vibrational state. Our results allow for rigorous testing of Rydberg interaction potentials and highlight the potential of quantum gas microscopy for molecular physics.
典型双原子分子的亚纳米级尺寸阻碍了人们对其组成部分的直接光学访问。由两个高度激发的里德伯原子组成的里德伯巨二聚体束缚态具有易于超过光波长的原子间距离。我们报告了在光学晶格中超冷铷原子气体中直接微观观察和详细表征此类分子的情况。键长约为 0.7 微米，与小细菌的大小相当，与晶格的对角线距离相匹配。通过在初始二维原子阵列中激发对，我们解析了超过 50 个振动共振。利用我们的空间分辨检测，我们通过相关的原子损耗观察到巨二聚体，并通过选择振动状态证明了对分子取向的控制。我们的结果允许对里德伯相互作用势能进行严格测试，并突出了量子气体显微镜在分子物理中的潜力。
