Sign inversion in the lateral van der Waals force between an anisotropic particle and a plane with a hemispherical protuberance: an exact calculation

Abstract

We investigate the lateral van der Waals (vdW) force between an anisotropic polarizable particle and a perfectly conducting plane with a hemispherical protuberance with radius $R$. We predict, via an exact calculation, a sign inversion in the lateral vdW force, in the sense that, instead of pointing to the protuberance, in certain situations this force points to the opposite direction. In the literature, predictions of sign inversions in the lateral vdW force were based on perturbative solutions, valid when the height of the protuberance is very small when compared to the distance $z_0$ between the particle and the plane. Here, taking into account exact formulas, we investigate how such nontrivial geometric effect depends on the ratio $R/z_0$, and how the particle orientation and anisotropy affect this sign inversion.

arXiv comment6 pages, 6 figures

References in corpus (19)

• Asymptotics of the dispersion interaction: analytic benchmarks for van der Waals energy functionals
• Nonuniversality of the dispersion interaction: analytic benchmarks for van der Waals energy functionals
• Casimir repulsion between metallic objects in vacuum
• Casimir-Polder interaction between a polarizable particle and a plate with a hole
• Physical Adsorption at the Nanoscale: Towards Controllable Scaling of the Substrate-Adsorbate van der Waals Interaction
• Force on a neutral atom near conducting microstructures
• Impact of anisotropy on the interaction of an atom with a one-dimensional nano-grating
• Fundamental limits to attractive and repulsive Casimir--Polder forces
• Optical torque on a two-level system near a strongly nonreciprocal medium
• Casimir-Polder interaction between an atom and a dielectric slab
• Casimir--Polder force between anisotropic nanoparticles and gently curved surfaces
• Casimir-Polder force and torque for anisotropic molecules close to conducting planes and their effects on CO${}_2$
• Image method in the calculation of the van der Waals force between an atom and a conducting surface
• Repulsive van der Waals interaction between a quantum particle and a conducting toroid
• Finite size effects and non-additivity in the van der Waals interaction
• Geometrical dependence in Casimir-Polder repulsion
• Peak, valley and intermediate regimes in the lateral van der Waals force
• Sign inversion in the lateral van der Waals force
• Regimes of the lateral van der Waals force in the presence of dielectrics