空间激活系统中相变的不同路径
Distinct routes to phase transitions in spatial activation systems
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中文总结 AI 辅助
本文揭示空间激活系统的相变由相互作用范围控制，存在连续、一阶、混合阶等不同相变路径，发现亚稳态及微观扰动可触发宏观级联，建立了微观与宏观行为的联系。
中文摘要 AI 辅助
阈值驱动的激活现象支配着广泛的集体行为，但其空间系统中相变的微观起源仍有待阐明。本文表明，空间激活系统会经历多条不同的相变路径，这些路径由单一参数——相互作用范围所控制。我们揭示了一个统一的相图，其中包含连续相变、一阶相变和混合阶相变，并证明两种突变式相变源于完全不同的机制：成核驱动的前沿传播和临界成核。这些路径呈现出不同的动力学标度，建立了微观激活动力学与宏观临界行为之间的直接联系。我们还识别出一种亚稳态，在该状态下，仅通过随机激活无法实现全局激活，但可通过局域激活触发。在该区域中，临界激活核保持有限且与系统大小无关，这意味着任意大的系统在随机扰动下都能保持稳定，但对局域扰动极为敏感。该相的出现是突变式的，揭示了集体动力学对微小参数变化的极端敏感性。这些结果为空间激活系统的相变建立了一个机制框架，并揭示了微观扰动如何触发宏观级联。
英文摘要
Threshold-driven activation governs a wide range of collective phenomena, yet the microscopic origins of its phase transitions in spatial systems remain unresolved. Here, we show that spatial activation systems undergo multiple distinct routes to phase transitions, controlled by a single parameter---the interaction range. We uncover a unified phase diagram featuring continuous, first-order, and mixed-order transitions, and demonstrate that the two abrupt transitions arise from fundamentally different mechanisms: nucleation-driven front propagation and critical branching. These routes exhibit distinct dynamical scaling, establishing a direct link between microscopic activation dynamics and macroscopic critical behavior. We further identify a metastable phase in which global activation cannot be achieved by random activation alone, but can be triggered by localized seeds. In this regime, the critical activation nucleus remains finite and independent of system size, implying that arbitrarily large systems can remain stable under random perturbations yet highly vulnerable to localized triggers. The onset of this phase is abrupt, revealing an extreme sensitivity of collective dynamics to small parameter changes. These results establish a mechanistic framework for phase transitions in spatial activation systems and reveal how microscopic perturbations can trigger macroscopic cascades.
