The mechanistic origin of branching-driven nucleation in abrupt phase transitions

TL;DR

This paper presents a theoretical framework explaining how nucleation propagation and cascading processes drive abrupt phase transitions, with implications for understanding microscopic mechanisms across various systems.

Contribution

It introduces a novel model based on internal node dependencies that generalizes nucleation-driven phase transition mechanisms to finite dependency ranges.

Findings

Nucleation propagation is preceded by a slow cascading process.

The model generalizes to include finite dependency ranges.

Experimental verification is possible through thermal diffusion control.

Abstract

Phase transitions are the macroscopic manifestation of microscopic processes that drive a system towards a new state. The detailed evolution of these processes, particularly in abrupt phase transitions, are currently not fully understood. Here, we introduce a theoretical framework based on internal node dependencies within a single-layer lattice. Crucially, we demonstrate that the fundamental mechanism underlying abrupt transitions is nucleation propagation preceded by a slow cascading process which scales with the range of dependencies. Our findings show that the synergy between these two distinct stages is essential for the occurrence of an abrupt transition. The first stage of a slow cascading mechanism was recently observed experimentally in superconducting layered materials, where heat acts as the dependency links, for the limit of infinite dependency range. Our model thus generalizes the framework to include finite dependency ranges, revealing previously unobserved mechanisms that could be experimentally verified through controlling the range of thermal diffusion in the material. As a universal mechanism, our model provides a robust method to test nucleation-controlled phase transitions in multiple systems, providing a path to discover and understand microscopic mechanisms in phase transitions.