Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, USA.
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2018 Jun 29;120(26):260602. doi: 10.1103/PhysRevLett.120.260602.
We demonstrate pretransition effects in space-time in trajectories of systems in which the dynamics displays a first-order phase transition between distinct dynamical phases. These effects are analogous to those observed for thermodynamic first-order phase transitions, most notably the hydrophobic effect in water. Considering the (infinite temperature) East model as an elementary example, we study the properties of "space-time solvation" by examining trajectories where finite space-time regions are conditioned to be inactive in an otherwise active phase. We find that solvating an inactive region of space-time within an active trajectory shows two regimes in the dynamical equivalent of solvation free energy: an "entropic" small solute regime in which uncorrelated fluctuations are sufficient to evacuate activity from the solute, and an "energetic" large solute regime which involves the formation of a solute-induced inactive domain with an associated active-inactive interface bearing a dynamical interfacial tension. We also show that as a result of this dynamical interfacial tension there is a dynamical analog of the hydrophobic collapse that drives the assembly of large hydrophobes in water. We discuss the general relevance of these results to the properties of dynamical fluctuations in systems with slow collective relaxation such as glass formers.
我们在显示动力学之间具有不同动态相的一阶相变的系统的轨迹中，展示了时空的预相变效应。这些效应类似于在热力学一级相变中观察到的那些效应，最显著的是水的疏水效应。考虑到（无限温度）East 模型作为一个基本例子，我们通过研究在否则处于活跃相的有限时空区域被条件化为不活跃的轨迹，研究了“时空溶剂化”的性质。我们发现，在活跃轨迹中溶剂化一个不活跃的时空区域显示了在动力学溶剂化自由能中的两个区域：在足够的非相关涨落足以从溶剂中排空活性的“熵”小溶质区域，以及涉及形成具有相关的活性-不活性界面的溶质诱导的不活性域的“能量”大溶质区域，该界面具有动力学界面张力。我们还表明，由于这种动力学界面张力，存在类似于驱动水中大疏水物组装的疏水崩溃的动力学类比。我们讨论了这些结果对具有缓慢集体弛豫的系统（如玻璃形成体）中动力学涨落的性质的普遍相关性。
