We qualitatively investigate the effect of zero-point motion (ZPM) on the structure and properties of a film composed of quantum particles adsorbed on a graphite substrate. The amplitude of ZPM is controlled by a change of the particle mass while keeping the interactions fixed. In that sense it is assumed that the interactions can be controlled by future doping methods. The worm-algorithm path integral Monte Carlo (WAPIMC) method is applied to simulate this system in the grand-canonical ensemble, where particles can be exchanged with the external particle reservoir. Another method, namely the multiconfigurational time-dependent Hartree method for bosons is additionally applied to verify some of the WAPIMC results and to provide further information on the entropy and the condensate fraction. Several important findings are reported. It is found that ZPM plays an important role in defining order and disorder in the crystalline structure of the adsorbed film. The total energy of the film drops with a reduction in the amplitude of ZPM, that is, it becomes more negative which is an indication to stronger adsorption. For a few particle numbers, a significant condensate fraction is detected that however drops sharply at critical values of the ZPM amplitude. Most importantly, a connection is established between chaos, in coordinate as well as momentum space, and the Heisenberg uncertainty principle. The importance of the present study lies in the fact that adsorbed two-dimensional films serve as an excellent experimental testbed for demonstrating low-dimensional quantum phenomena in the ground state. The present examination contributes also to a further understanding of the properties of heavy quantum particles adsorbed on substrates.

中文翻译：

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零点运动对吸附在基底上的量子粒子特性的影响

我们定性研究了零点运动（ZPM）对由吸附在石墨基板上的量子粒子组成的薄膜的结构和性能的影响。 ZPM 的振幅由粒子质量的变化控制，同时保持相互作用固定。从这个意义上说，假设相互作用可以通过未来的掺杂方法来控制。应用蠕虫算法路径积分蒙特卡罗（WAPIMC）方法在大正则系综中模拟该系统，其中粒子可以与外部粒子库交换。另外还应用另一种方法，即玻色子的多构型时间相关 Hartree 方法来验证一些 WAPIMC 结果并提供有关熵和凝聚分数的进一步信息。报告了一些重要的发现。研究发现，ZPM 在定义吸附膜晶体结构的有序和无序方面起着重要作用。薄膜的总能量随着 ZPM 幅度的减小而下降，也就是说，它变得更负，这表明吸附更强。对于少数颗粒数量，检测到显着的凝结物部分，但在 ZPM 振幅的临界值处急剧下降。最重要的是，坐标空间和动量空间中的混沌与海森堡测不准原理之间建立了联系。本研究的重要性在于，吸附二维薄膜可以作为展示基态低维量子现象的优秀实验平台。本研究还有助于进一步了解吸附在基板上的重量子粒子的特性。