AI 中文总结
该研究通过量子蒙特卡洛模拟证实三维自由超流氦-4表面存在氦-3原子束缚态，还发现小氦-4团簇边缘的氦-3束缚态存在于所有碱金属基底上。
AI 中文摘要
量子蒙特卡洛模拟证实，三维自由超流氦-4表面存在单个氦-3原子的束缚态，该束缚态定域在厚度约10埃的低密度氦-4表层内，相对于真空的结合能约为4开尔文。当温度升高至约1开尔文以上时，氦-3原子会脱离表面溶解进超流体中。二维情形则完全不同，氦-3原子被排除在超流体之外，不存在表面束缚态。本文还给出了氦-3原子与吸附在弱基底上的纳米级氦-4团簇结合的结果，该物理系统或可用于观测扩展表面的部分预测物理现象。研究表明，氦-3原子定域在足够小（数十个原子量级）的团簇边缘的束缚态，不仅如此前报道的那样存在于铯基底上，还存在于所有碱金属基底上。
英文摘要
Quantum Monte Carlo simulations confirm the existence of a bound state of a single He-3 atom at a free superfluid He-4 surface in three dimensions, localized within a ~10-A thick low-density He-4 surface layer, with a binding energy of approximately 4 K with respect to vacuum. As the temperature is raised above ~ 1 K the He-3 atom leaves the surface to dissolve into the superfluid. The situation is entirely different in two dimensions, as the He-3 atom is excluded from the superfluid and no surface bound state exists. Results are also presented for the a He-3 atom binding to nanoscale size He-4 clusters adsorbed on weak substrates, a physical system that may allow for the observation of some of the physics predicted for extended surfaces. It is shown that a He-3 bound state localized at the perimeter of sufficiently small (a few tens of atoms) clusters exists not just on Cs, as previously reported, but on all alkali substrates.
Comments7 pages, 6 figures
