Densest helical structures of hard spheres in narrow confinement: An analytic derivation

The emergence of helicity from the densest possible packings of equal-sized hard spheres in narrow cylindrical confinement can be understood in terms of a density maximization of repeating microconfigurations. At any cylinder-to-sphere diameter ratio D∈(1+3/2,2), a sphere can only be in contact with...

Full description

Bibliographic Details
Main Authors: Ho-Kei Chan, Yuqian Wang, Hongyu Han
Format: Article
Language:English
Published: AIP Publishing LLC 2019-12-01
Series:AIP Advances
Online Access:http://dx.doi.org/10.1063/1.5131318
_version_ 1819138374873645056
author Ho-Kei Chan
Yuqian Wang
Hongyu Han
author_facet Ho-Kei Chan
Yuqian Wang
Hongyu Han
author_sort Ho-Kei Chan
collection DOAJ
description The emergence of helicity from the densest possible packings of equal-sized hard spheres in narrow cylindrical confinement can be understood in terms of a density maximization of repeating microconfigurations. At any cylinder-to-sphere diameter ratio D∈(1+3/2,2), a sphere can only be in contact with its nearest and second nearest neighbors along the vertical z-axis, and the densest possible helical structures are results of a minimized vertical separation between the first sphere and the third sphere for every consecutive triplet of spheres. By considering a density maximization of all microscopic triplets of mutually touching spheres, we show, by both analytical and numerical means, that the single helix at D∈(1+3/2,1+43/7) corresponds to a repetition of the same triplet configuration and that the double helix at D∈(1+43/7,2) corresponds to an alternation between two triplet configurations. The resulting analytic expressions for the positions of spheres in these helical structures could serve as a theoretical basis for developing novel chiral materials.
first_indexed 2024-12-22T11:05:46Z
format Article
id doaj.art-b88ee0aa1acc484a93cbcae3d2efcd65
institution Directory Open Access Journal
issn 2158-3226
language English
last_indexed 2024-12-22T11:05:46Z
publishDate 2019-12-01
publisher AIP Publishing LLC
record_format Article
series AIP Advances
spelling doaj.art-b88ee0aa1acc484a93cbcae3d2efcd652022-12-21T18:28:20ZengAIP Publishing LLCAIP Advances2158-32262019-12-01912125118125118-810.1063/1.5131318Densest helical structures of hard spheres in narrow confinement: An analytic derivationHo-Kei Chan0Yuqian Wang1Hongyu Han2School of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, People’s Republic of ChinaSchool of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, People’s Republic of ChinaSchool of Science, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, People’s Republic of ChinaThe emergence of helicity from the densest possible packings of equal-sized hard spheres in narrow cylindrical confinement can be understood in terms of a density maximization of repeating microconfigurations. At any cylinder-to-sphere diameter ratio D∈(1+3/2,2), a sphere can only be in contact with its nearest and second nearest neighbors along the vertical z-axis, and the densest possible helical structures are results of a minimized vertical separation between the first sphere and the third sphere for every consecutive triplet of spheres. By considering a density maximization of all microscopic triplets of mutually touching spheres, we show, by both analytical and numerical means, that the single helix at D∈(1+3/2,1+43/7) corresponds to a repetition of the same triplet configuration and that the double helix at D∈(1+43/7,2) corresponds to an alternation between two triplet configurations. The resulting analytic expressions for the positions of spheres in these helical structures could serve as a theoretical basis for developing novel chiral materials.http://dx.doi.org/10.1063/1.5131318
spellingShingle Ho-Kei Chan
Yuqian Wang
Hongyu Han
Densest helical structures of hard spheres in narrow confinement: An analytic derivation
AIP Advances
title Densest helical structures of hard spheres in narrow confinement: An analytic derivation
title_full Densest helical structures of hard spheres in narrow confinement: An analytic derivation
title_fullStr Densest helical structures of hard spheres in narrow confinement: An analytic derivation
title_full_unstemmed Densest helical structures of hard spheres in narrow confinement: An analytic derivation
title_short Densest helical structures of hard spheres in narrow confinement: An analytic derivation
title_sort densest helical structures of hard spheres in narrow confinement an analytic derivation
url http://dx.doi.org/10.1063/1.5131318
work_keys_str_mv AT hokeichan densesthelicalstructuresofhardspheresinnarrowconfinementananalyticderivation
AT yuqianwang densesthelicalstructuresofhardspheresinnarrowconfinementananalyticderivation
AT hongyuhan densesthelicalstructuresofhardspheresinnarrowconfinementananalyticderivation