Temporal and structural characteristics of a two dimensional gas of hard needles

TL;DR

This study uses event-oriented molecular dynamics to explore the dynamics of a 2D gas of hard needles, revealing complex rotational behavior and a three-stage mean squared displacement at high densities.

Contribution

It provides new insights into the rotational dynamics and phase behavior of 2D hard needle gases through detailed simulations.

Findings

Rotational diffusion slows down with increasing density.

A three-stage regime in rotational mean squared displacement is observed.

No positional ordering occurs despite complex rotational dynamics.

Abstract

We have simulated the dynamics of a 2D gas of hard needles by event-oriented molecular dynamics. Various quantities namely translational and rotational diffusion constants and intermediate self scattering function have been explored and their dependence on density is obtained. Despite absence of positional ordering, the rotational degree of freedom behaves nontrivially. Slowing down is observed in the angular part of the motion. It is shown that above a certain density the rotational mean squared displacement exhibits a three stage regime including a plateau.