A hybrid helical structure of hard sphere packing from sequential deposition

TL;DR

This paper reports the discovery of a novel hybrid helical structure of hard spheres in cylindrical confinement, generated through a sequential deposition method that manipulates a few spheres to create new dense packing configurations.

Contribution

It introduces a new hybrid helical structure formed by sequential deposition, expanding the understanding of possible dense packings in confined hard sphere systems.

Findings

Discovery of a hybrid helical structure combining features of single and double helices.

Demonstration that small template modifications can lead to new dense packing structures.

Validation that sequential deposition can be used to explore novel sphere packings.

Abstract

A hybrid helical structure of equal-sized hard spheres in cylindrical confinement was discovered as a 'by-product' of the recently developed sequential deposition approach [Physical Review E 84, 050302(R) (2011)] for constructing the densest possible packings of such systems. Unlike the conventional triple-helix structure where its three strands of spheres are packed densely to form triads of close-packed, mutually touching spheres, in this novel helical phase only two of its three strands of spheres are packed in this densest arrangement and the overall structure resembles a hybrid of the single and the double helix. This article explains how this previously unknown structure can be constructed via the abovementioned sequential deposition of spheres, which involves manipulating the positions of a few spheres to create a template for the deposition process. The findings show that it is possible to discover new structures through varying only the configuration of few spheres within the template, where this approach relies on a sensitive dependence of the deposition-generated structures on the template.