Institute of Computational Engineering Sciences, University of Luxembourg, L-4365, Luxembourg City, Luxembourg.
Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, 35131, Padova, Italy.
Nat Commun. 2020 Apr 3;11(1):1651. doi: 10.1038/s41467-020-15480-w.
Anomalous proximity effects have been observed in adhesive systems ranging from proteins, bacteria, and gecko feet suspended over semiconductor surfaces to interfaces between graphene and different substrate materials. In the latter case, long-range forces are evidenced by measurements of non-vanishing stress that extends up to micrometer separations between graphene and the substrate. State-of-the-art models to describe adhesive properties are unable to explain these experimental observations, instead underestimating the measured stress distance range by 2-3 orders of magnitude. Here, we develop an analytical and numerical variational approach that combines continuum mechanics and elasticity with quantum many-body treatment of van der Waals dispersion interactions. A full relaxation of the coupled adsorbate/substrate geometry leads us to conclude that wavelike atomic deformation is largely responsible for the observed long-range proximity effect. The correct description of this seemingly general phenomenon for thin deformable membranes requires a direct coupling between quantum and continuum mechanics.
已经在从蛋白质、细菌和壁虎脚等悬浮在半导体表面的黏附系统，到石墨烯与不同基底材料之间的界面等范围中观察到异常近程效应。在后一种情况下，通过测量在石墨烯和基底之间延伸至微米分离的非零应力，证明了存在长程力。用于描述黏附特性的最先进模型无法解释这些实验观察结果，而是低估了测量的应力距离范围 2-3 个数量级。在这里，我们开发了一种分析和数值变分方法，将连续介质力学和弹性与范德华色散相互作用的量子多体处理相结合。对耦合吸附剂/基底几何形状的完全弛豫使我们得出结论，波状原子变形在很大程度上是导致观察到的长程近程效应的原因。对于薄的可变形膜，正确描述这种看似普遍的现象需要量子力学和连续介质力学之间的直接耦合。
