| Autor: |
Chan, Ho-Kei, Wang, Yuqian, Han, Hongyu |
| Předmět: |
|
| Zdroj: |
AIP Advances; Dec2019, Vol. 9 Issue 12, p1-8, 8p |
| Abstrakt: |
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 + 4 3 / 7) corresponds to a repetition of the same triplet configuration and that the double helix at D ∈ (1 + 4 3 / 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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
