Particle dynamics in fluids with random interactions

TL;DR

This study investigates the complex particle dynamics in a multi-component Lennard-Jones fluid with all particles distinct, revealing how lowering temperature amplifies heterogeneity and complexity in particle trajectories.

Contribution

It provides a detailed molecular dynamics analysis of particle trajectories in a multi-component LJ fluid, highlighting the effects of temperature on dynamic heterogeneity and structural ordering.

Findings

Increased complexity of particle dynamics at lower temperatures.

Distinct distributions of angles, displacements, and waiting times compared to one-component fluids.

Enhanced heterogeneity due to neighborhood identity ordering.

Abstract

We study the dynamics of particles in a multi-component 2d Lennard-Jones (LJ) fluid in the limiting case where {\it all the particles are different} (APD). The equilibrium properties of this APD system were studied in our earlier work [J.~Chem.~Phys.~142, 051104]. We use molecular dynamics simulations to investigate the statistical properties of particle trajectories in a temperature range covering both normal and supercooled fluid states. We calculate the mean-square displacement as well as angle, displacement and waiting time distributions, and compare the results with those for one-component LJ fluid. As temperature is lowered, the dynamics of the APD system becomes increasingly complex, as the intrinsic difference between the particles is amplified by neighborhood identity ordering and by the heterogeneous structure of the supercooled state.