Non-touching nanoparticle diclusters bound by repulsive and attractive Casimir forces

TL;DR

This paper demonstrates how stable, non-touching dielectric nanoparticle clusters can be achieved using Casimir forces in fluid environments, with stability influenced by material and geometric dispersion effects.

Contribution

It introduces a scheme for stable Casimir suspension of dielectric objects in fluids, validated through various geometries, and highlights the role of dispersion properties in stability.

Findings

Stable dielectric nanoparticle clusters are possible in fluid environments.

Material and geometric dispersion significantly affect stability behavior.

Different geometries exhibit distinct stability characteristics.

Abstract

We present a scheme for obtaining stable Casimir suspension of dielectric nontouching objects immersed in a fluid, validated here in various geometries consisting of ethanol-separated dielectric spheres and semi-infinite slabs. Stability is induced by the dispersion properties of real dielectric (monolithic) materials. A consequence of this effect is the possibility of stable configurations (clusters) of compact objects, which we illustrate via a "molecular" two-sphere dicluster geometry consiting of two bound spheres levitated above a gold slab. Our calculations also reveal a strong interplay between material and geometric dispersion, and this is exemplified by the qualitatively different stability behavior observed in planar versus spherical geometries.