Joint Quantum Centre (JQC) Durham/Newcastle, Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom.
Phys Rev Lett. 2013 Nov 15;111(20):203004. doi: 10.1103/PhysRevLett.111.203004. Epub 2013 Nov 12.
We show theoretically that ultracold hydrogen atoms have very favorable properties for sympathetic cooling of molecules to microkelvin temperatures. We calculate the potential energy surfaces for spin-polarized interactions of H atoms with the prototype molecules NH(3Σ-) and OH(2Π) and show that they are shallow (50 to 80 cm(-1)) and only weakly anisotropic. We carry out quantum collision calculations on H+NH and H+OH and show that the ratio of elastic to inelastic cross sections is high enough to allow sympathetic cooling from temperatures well over 1 K for NH and around 250 mK for OH.
我们从理论上表明，超冷氢原子对于将分子冷却到微开尔文温度的分子的共鸣具有非常有利的性质。我们计算了 H 原子与原型分子 NH(3Σ-)和 OH(2Π)之间的自旋极化相互作用的势能表面，并表明它们是浅的（50 至 80 cm(-1))并且仅弱各向异性。我们对 H+NH 和 H+OH 进行了量子碰撞计算，并表明弹性与非弹性截面的比值足够高，足以允许 NH 从远高于 1 K 的温度和 OH 从约 250 mK 的温度进行共鸣冷却。
