Trapping in a Casimir Force Set-Up Controlled by Solution Permeability

TL;DR

This paper presents a system that controls Casimir forces between a sphere and a surface by adjusting solution permeability, enabling significant changes in trapping distances through modifications in particle size.

Contribution

The study introduces a novel method to tune Casimir forces using solution permeability and particle size adjustments, expanding control over quantum fluctuation-induced forces.

Findings

Casimir force can be switched between attraction and repulsion.

Trapping distances vary by several orders of magnitude.

Control achieved through particle size modification in a magnetic fluid.

Abstract

We have designed a system enabling tuning Casimir attraction/repulsion transitions between a polystyrene sphere attached to an atomic force microscope tip near a Teflon surface in a magnetic fluid mixture. Notably, the trapping distances can be changed by several orders of magnitude by changes in zero-frequency transverse electric contributions to the Casimir force. We demonstrate that this can be achieved via modifications in the average diameter for the magnetite particles while keeping the magnetite volume fractions fixed.