Memory effects on the statistics of fragmentation

TL;DR

This study uses molecular dynamics simulations to analyze how initial thermal conditions influence the statistical distribution of fragments in a 2D Lennard-Jones system undergoing fragmentation, revealing phase-dependent scaling behavior.

Contribution

It demonstrates that the fragmentation statistics depend on the initial thermal state, establishing a link between system phase and the scaling exponent of fragment size distribution.

Findings

Fragment size distribution follows a specific scaling form.

The scaling exponent varies with the initial temperature.

System phase determines the non-universal behavior of fragmentation.

Abstract

We investigate through extensive molecular dynamics simulations the fragmentation process of two-dimensional Lennard-Jones systems. After thermalization, the fragmentation is initiated by a sudden increment to the radial component of the particles' velocities. We study the effect of temperature of the thermalized system as well as the influence of the impact energy of the ``explosion'' event on the statistics of mass fragments. Our results indicate that the cumulative distribution of fragments follows the scaling ansatz $F(m)\propto m^{-\alpha}\exp{[-(m/m_0)^\gamma]}$, where $m$ is the mass, $m_0$ and $\gamma$ are cutoff parameters, and $\alpha$ is a scaling exponent that is dependent on the temperature. More precisely, we show clear evidence that there is a characteristic scaling exponent $\alpha$ for each macroscopic phase of the thermalized system, i.e., that the non-universal behavior of the fragmentation process is dictated by the state of the system before it breaks down.