The hexatic phase of the two-dimensional hard disks system

TL;DR

This paper provides Monte Carlo simulation evidence for the existence of a hexatic phase in the two-dimensional hard disk system, supporting theoretical predictions and clarifying the nature of the phase transition.

Contribution

It presents large-scale Monte Carlo simulations demonstrating the hexatic phase and its properties, confirming theoretical predictions for the 2D hard disk system.

Findings

Confirmation of hexatic phase existence in 2D hard disks

Scaling behavior consistent with Kosterlitz-Thouless theory

Hexatic phase outside a first-order transition

Abstract

We report Monte Carlo results for the two-dimensional hard disk system in the transition region. Simulations were performed in the NVT ensemble with up to 1024^2 disks. The scaling behaviour of the positional and bond-orientational order parameter as well as the positional correlation length prove the existence of a hexatic phase as predicted by the Kosterlitz-Thouless-Halperin-Nelson-Young theory. The analysis of the pressure shows that this phase is outside a possible first-order transition.