RUI: Helium Adsorption on Alkali Surfaces and Graphite: Computer Simulation Studies

9802803 Boninsegni这是一个本科院校研究（RUI）奖，用于氦物理吸附的理论研究项目。利用路径积分蒙特卡罗（PIMC）方法对氦在碱表面和石墨表面的吸附过程进行了计算机模拟。可用的、真实的原子间电位将被用来模拟氦原子之间以及氦原子与衬底之间的相互作用。拟议研究工作的具体目标将是研究碱金属表面以及石墨基板上的4He吸附物的物理性质。本研究的统一主题是物理吸附，这是凝聚态物理学中非常有趣的话题，迄今为止进行的数值模拟相对较少。这项研究也有望为诸如降维相变和单层超流动性等基本理论问题提供新的见解。PIMC方法可以说是目前最强大的数值工具，可以直接从微观哈密顿量计算量子多体系统的热力学性质。在本研究中使用该技术可以对涉及不同吸引力底物和量子吸附物的各种吸附现象进行定量预测；因此，它将有助于解释几个正在进行的涉及氦吸附的实验。这是一个本科院校研究（RUI）奖，用于支持氦在各种基质（包括石墨）上吸附的数值模拟程序。数值模拟将支持其他地方正在进行的许多实验。模拟还将提供对表面和单层超流动性的吸附物相变的见解。* * *

9802803 Boninsegni This is a Research at Undergraduate Institutions (RUI) Award for a theoretical program consisting of numerical studies of Helium physisorption. Computer simulations of Helium adsorbed on alkali surfaces and on graphite will be performed using the Path Integral Monte Carlo (PIMC) method. Available, realistic interatomic potentials will be adopted to model the interaction among Helium atoms, as well as between Helium atoms and the substrate. Specific objectives of the proposed research effort will be the study of the physical properties of a 4He adsorbate on the surface of alkali metals, as well as on a graphite substrate. The unifying theme of this research is the topic of physisorption, of great interest in condensed matter physics, and one where relatively little numerical simulation has been performed so far. This research is also expected to offer novel insight into such fundamental theoretical issues as phase transitions in reduced dimensions and monolayer superfluidity. The PIMC method is arguably the most powerful numerical tool currently available to calculate thermodynamic properties of quantum many-body systems directly from a microscopic Hamiltonian. The use of this technique in this research can afford quantitative predictions for a variety of adsorption phenomena involving differently attractive substrates and a quantum adsorbate; thus, it will help in the interpretation of several ongoing experiments involving Helium adsorption. %%% This is a Research at Undergraduate Institutions (RUI) Award to support a program of numerical simulation of the adsorption of Helium on various substrates including graphite. The numerical simulations will support a number of experiments being done elsewhere. The simulations will also provide insight into phase transitions of adsorbates on surfaces and on monolayer superfluidity. ***