Department of Applied Physics, Aalto University, 00076 Aalto, Finland.
Phys Rev E. 2018 Jan;97(1-1):012115. doi: 10.1103/PhysRevE.97.012115.
The complex zeros of partition functions were originally investigated by Lee and Yang to explain the behavior of condensing gases. Since then, Lee-Yang zeros have become a powerful tool to describe phase transitions in interacting systems. Today, Lee-Yang zeros are no longer just a theoretical concept; they have been determined in recent experiments. In one approach, the Lee-Yang zeros are extracted from the high cumulants of thermodynamic observables at finite size. Here we employ this method to investigate a phase transition in a molecular zipper. From the energy fluctuations in small zippers, we can predict the temperature at which a phase transition occurs in the thermodynamic limit. Even when the system does not undergo a sharp transition, the Lee-Yang zeros carry important information about the large-deviation statistics and its symmetry properties. Our work suggests an interesting duality between fluctuations in small systems and their phase behavior in the thermodynamic limit. These predictions may be tested in future experiments.
李-杨零点最初是由李政道和杨振宁为了解释凝聚态气体的行为而研究的。从那时起，李-杨零点就成为了描述相互作用系统相变的有力工具。如今，李-杨零点不再仅仅是一个理论概念；它们已经在最近的实验中得到了确定。在一种方法中，李-杨零点是从有限尺寸下热力学可观测量的高累积量中提取出来的。在这里，我们采用这种方法来研究分子拉链中的相变。从小拉链的能量涨落中，我们可以预测在热力学极限下发生相变的温度。即使系统没有发生急剧的转变，李-杨零点也携带了关于大偏差统计及其对称性质的重要信息。我们的工作表明，小系统中的涨落与其在热力学极限下的相行为之间存在有趣的对偶性。这些预测可以在未来的实验中进行检验。
