Packing Confined Hard Spheres Denser with Adaptive Prism Phases

TL;DR

This paper demonstrates that adaptive prism phases enable denser packing of hard spheres confined between parallel plates, with experimental and simulation evidence showing their effectiveness across various slit heights.

Contribution

It introduces the concept of adaptive prism phases that optimize packing density in confined hard sphere systems, supported by experiments and simulations.

Findings

Adaptive prism phases achieve higher packing densities.

Experimental and simulation results confirm the existence of these phases.

Close packings occur for specific slit heights just above three square layers.

Abstract

We show that hard spheres confined between two parallel hard plates pack denser with periodic adaptive prismatic structures which are composed of alternating prisms of spheres. The internal structure of the prisms adapts to the slit height which results in close packings for a range of plate separations, just above the distance where three intersecting square layers fit exactly between the plates. The adaptive prism phases are also observed in real-space experiments on confined sterically stabilized colloids and in Monte Carlo simulations at finite pressure.