Lighting the way to molecules, one by one When chemists run reactions, what they are really doing is mixing up an enormous number of reacting partners and then hoping that they collide productively. It is possible to manipulate atoms more deliberately with a scanning tunneling microscope tip, but the process is then confined to a surface. Liu et al. directly manipulated individual atoms with light to form single molecules in isolation (see the Perspective by Narevicius). They used optical tweezers of two different colors to selectively steer ultracold sodium (Na) and cesium (Cs) atoms together. A subsequent optical excitation formed NaCs. Science, this issue p. 900; see also p. 855 Optical tweezers at distinct wavelengths poise individual sodium and cesium atoms sufficiently close together to form a NaCs molecule. Chemical reactions typically proceed via stochastic encounters between reactants. Going beyond this paradigm, we combined exactly two atoms in a single, controlled reaction. The experimental apparatus traps two individual laser-cooled atoms [one sodium (Na) and one cesium (Cs)] in separate optical tweezers and then merges them into one optical dipole trap. Subsequently, photoassociation forms an excited-state NaCs molecule. The discovery of previously unseen resonances near the molecular dissociation threshold and measurement of collision rates are enabled by the tightly trapped ultracold sample of atoms. As laser-cooling and trapping capabilities are extended to more elements, the technique will enable the study of more diverse, and eventually more complex, molecules in an isolated environment, as well as synthesis of designer molecules for qubits.

中文翻译：

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从两个原子的库中构建一个分子

一一照亮分子之路 当化学家进行反应时，他们真正在做的是混合大量的反应伙伴，然后希望它们有效地发生碰撞。可以使用扫描隧道显微镜尖端更有意地操纵原子，但该过程仅限于表面。刘等人。直接用光操纵单个原子以形成孤立的单个分子（参见 Narevicius 的观点）。他们使用两种不同颜色的光镊选择性地将超冷钠 (Na) 和铯 (Cs) 原子控制在一起。随后的光激发形成了 NaCl。科学，这个问题 p。900；另见第。855 不同波长的光镊使单独的钠和铯原子充分靠近以形成 NaCs 分子。化学反应通常通过反应物之间的随机相遇进行。超越这种范式，我们在一个受控的反应中恰好结合了两个原子。该实验装置在单独的光镊中捕获两个单独的激光冷却原子 [一个钠 (Na) 和一个铯 (Cs)]，然后将它们合并成一个光学偶极子陷阱。随后，光缔合形成激发态 NaCs 分子。通过紧密捕获的超冷原子样本，可以发现分子解离阈值附近以前未见的共振和碰撞率的测量。随着激光冷却和捕获能力扩展到更多元素，该技术将能够在孤立环境中研究更多样、最终更复杂的分子，