Columnar structures of soft spheres: Metastability and hysteresis

TL;DR

This paper investigates the structural phases, metastability, and hysteresis of soft spheres in cylindrical channels, extending the phase diagram and exploring non-equilibrium transitions relevant for experimental systems.

Contribution

It extends the phase diagram of soft sphere packings in cylinders up to D/d=2.714 and examines hysteretic transitions under varying conditions.

Findings

Extended phase diagram up to D/d=2.714

Identified hysteretic structural transitions

Provided stability diagrams and illustrative videos

Abstract

Previously we reported on the stable (i.e. minimal enthalpy) structures of soft monodisperse spheres in a long cylindrical channel. Here, we present further simulations, which significantly extend the original phase diagram up to D/d = 2.714 (ratio of cylinder and sphere diameters), where the nature of densest sphere packing changes. However, macroscopic systems of this kind are not confined to the ideal equilibrium states of this diagram. Consequently, we explore some of the structural transitions to be expected as experimental conditions are varied; these are in general hysteretic. We represent these transitions in a stability diagram for a representative case. Illustrative videos are included in the supplemental material.