Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia.
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
J Chem Phys. 2019 Sep 21;151(11):114502. doi: 10.1063/1.5116176.
Accurate analysis of pair correlations in condensed matter allows us to establish relations between structures and thermodynamic properties and, thus, is of high importance for a wide range of systems, from solids to colloidal suspensions. Recently, the interpolation method (IM) that describes satisfactorily the shape of pair correlation peaks at short and at long distances has been elaborated theoretically and using molecular dynamics simulations, but it has not been verified experimentally as yet. Here, we test the IM by particle-resolved studies with colloidal suspensions and with complex (dusty) plasmas and demonstrate that, owing to its high accuracy, the IM can be used to experimentally measure parameters that describe interaction between particles in these systems. We used three- and two-dimensional colloidal crystals and monolayer complex (dusty) plasma crystals to explore suitability of the IM in systems with soft to hard-sphere-like repulsion between particles. In addition to the systems with pairwise interactions, if many-body interactions can be mapped to the pairwise ones with some effective (e.g., density-dependent) parameters, the IM could be used to obtain these parameters. The results reliably show that the IM can be effectively used for analysis of pair correlations and interactions in a wide variety of systems and therefore is of broad interest in condensed matter, complex plasma, chemical physics, physical chemistry, materials science, and soft matter.
准确分析凝聚态物质中的对关联，使我们能够建立结构与热力学性质之间的关系，因此对从固体到胶体悬浮液等广泛的系统都具有重要意义。最近，已经从理论和分子动力学模拟两方面详细阐述了能够很好地描述短程和长程对关联峰形状的内插法（IM），但尚未进行实验验证。在这里，我们使用胶体悬浮液和复杂（尘埃）等离子体的颗粒分辨研究来检验 IM，并证明由于其高精度，IM 可用于实验测量描述这些系统中颗粒间相互作用的参数。我们使用了三维和二维胶体晶体和单层复杂（尘埃）等离子体晶体来探索 IM 在具有软球到硬球样排斥的系统中的适用性。除了具有对相互作用的系统之外，如果可以将多体相互作用映射到具有某些有效（例如，密度相关）参数的对相互作用，则可以使用 IM 来获得这些参数。结果可靠地表明，IM 可有效地用于分析各种系统中的对关联和相互作用，因此在凝聚态物质、复杂等离子体、物理化学、化学物理、材料科学和软物质等领域具有广泛的兴趣。
