Features of the fluctuation -electromagnetic interaction between a small conducting particle and polarizable medium

TL;DR

This paper investigates the fluctuation electromagnetic interaction between small conducting particles and polarizable surfaces, highlighting the roles of magnetic coupling, temperature, and retardation effects with numerical examples.

Contribution

It introduces new features of fluctuation electromagnetic interactions considering magnetic effects, temperature dependence, and retardation, which were not previously detailed.

Findings

Magnetic coupling significantly influences the interaction force.

Interaction depends on distance, temperature, and material properties.

Numerical estimates for copper particles and substrates are provided.

Abstract

For the first time, new important features of the fluctuation electromagnetic interaction between a small conducting particle and a smooth surface of polarizable medium (both dielectric and metallic) are worked out. The particle is characterized by classical electric and magnetic polarizabilities. The temperature dependence and retardation effects are explicitly taken into account. The resulting interaction force between a metallic particle and the surface of metal proves to be determined to great extent by magnetic coupling and reveals specific dependences on distance, temperature, particle radius and material properties of contacting materials. Numerical estimations are given in the case of a Cu particle above a smooth Cu substrate at different particle radius and temperature of the system.