Nonlinearity in the dynamics of photoinduced nucleation process

TL;DR

This study investigates the nonlinear dynamics of photoinduced nucleation in molecular crystals, revealing that nucleation occurs only above a threshold excitation energy and exhibits a nonlinear relationship with excitation strength.

Contribution

The paper introduces a numerical model demonstrating the threshold-dependent and nonlinear nature of photoinduced nucleation in molecular crystals.

Findings

Nucleation requires a minimum cluster of excited molecules.

The fraction of converted molecules depends nonlinearly on excitation strength.

Threshold behavior explains experimental observations in various materials.

Abstract

Nonlinear dynamics of photoinduced cooperative phenomena is studied by numerical calculations on a model of molecular crystals. We found that the photoinduced nucleation process is triggered only when certain amount of excitation energy is supplied in a narrow part of the system, i.e., there exists a smallest cluster of excited molecules which makes the nucleation possible. As a result, the portion of the cooperatively converted molecules is nonlinearly dependent on the photoexcitation strength, which has been observed in various materials.