In this paper we address, both experimentally and theoretically, the very grazing scattering of He atoms off KCl(001) with incidence along the $\langle 100\rangle$ channel. Our theoretical model combines a semiquantum description of the scattering dynamics and a high-precision interaction potential. By means of a thorough analysis of the quantum phase for in-plane scattering and rainbow trajectories, we are able to connect the presence of the physisorption well with the significant enhancements of the corrugation and rainbow angle, relative to the hard corrugated wall predictions. We trace this connection to dynamical effects on the incident and scattered beams due to their traversing of the physisorption well. Finally, we show that the inclusion of van der Waals interactions in the potential improves the theoretical accord with experiments for both the corrugation and the rainbow angle.

中文翻译：

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在 KCl(001) 的掠入射快速 He 原子衍射中，动力学效应作为范德华相互作用的窗口

在本文中，我们从实验和理论上讨论了 He 原子从 KCl(001) 沿入射方向的非常掠射散射 $〈100〉$渠道。我们的理论模型结合了散射动力学的半量子描述和高精度相互作用势。通过对面内散射和彩虹轨迹的量子相位进行彻底分析，我们能够将物理吸附的存在与波纹和彩虹角的显着增强联系起来，相对于硬波纹壁预测。我们将这种联系与入射光束和散射光束的动力学效应联系起来，因为它们穿过物理吸附井。最后，我们表明在势能中包含范德华相互作用可以提高波纹和彩虹角实验的理论一致性。