On Short-Range Enhancement of Van-der-Waals Forces

TL;DR

This paper demonstrates that van der Waals forces between highly polarizable nanoparticles are significantly enhanced at short distances, with nonlinear effects playing a crucial role in accurately describing this phenomenon without resulting in repulsive forces.

Contribution

It provides a detailed analysis of short-range van der Waals enhancement in highly polarizable nanoparticles, emphasizing the importance of nonlinear effects in the force calculations.

Findings

Van der Waals forces are greatly enhanced at distances below R_0.

Nonlinear effects are essential for accurate force description.

Nonlinear treatment does not produce repulsive forces, contrary to some claims.

Abstract

We show that for nanoparticles with giant polarizability $\alpha$ (a prominent example being the recently studied Na$_{14}$F$_{13}$ molecular clusters) van der Waals forces are significantly enhanced at interparticle distances shorter than $R_0=(\alpha/2\pi\epsilon_0)^{1/3}$. For an adequate description of this phenomenon, nonlinear effects must be taken into account. We show that, contrary to some theoretical claims, an accurate treatment of nonlinearity does not lead to any repulsive forces.