Theory for the Nonlinear Ultrafast Dynamics of Small Clusters after Ionization

TL;DR

This paper investigates the ultrafast nonlinear dynamics of small clusters post-ionization, revealing how initial conditions and temperature influence fragmentation and stability, with implications for understanding cluster relaxation processes.

Contribution

It provides a theoretical framework for the nonlinear ultrafast dynamics of small clusters after ionization, including temperature-dependent fragmentation behavior and Lyapunov exponent analysis.

Findings

Fragmentation-time distributions vary with initial temperature.

A significant change in fragmentation occurs at melting point.

Lyapunov exponent increases markedly after ionization.

Abstract

The ultrafast relaxation of small clusters immediately after ionization is studied. For small Hg$_n$ clusters we determine the fragmentation-time distributions induced by ionization. A dramatic change of the fragmentation behaviour occurs when the temperature before ionization reaches the melting point of the neutral clusters. The ultrafast dynamics depends nonlinearly on initial conditions regarding atomic positions and velocities. The resultant largest Lyapunov exponent increases strongly upon ionization.