Thermal Casimir interactions in multi-particle systems: scattering channel approach

TL;DR

This paper analyzes multi-particle thermal Casimir interactions using a scattering channel approach, revealing how geometry and polarization mixing influence entropy and interaction characteristics.

Contribution

It introduces a detailed scattering path framework for multi-particle Casimir interactions, emphasizing the impact of geometry and channel types on entropy and interaction behavior.

Findings

Negativity and nonmonotonicity in Casimir entropy are common.

Thermal multi-particle scattering effects are significant, zero-temperature effects are negligible.

Path geometry and polarization mixing influence interaction properties.

Abstract

Multi-particle thermal Casimir interactions are investigated, mostly in terms of the Casimir entropy, from the point of view based on multiple-scattering processes. The geometry of the scattering path is depicted in detail, and the contributions from different types of channels, namely the transverse, longitudinal and mixing channels, are demonstrated. The geometry of the path can strongly influence the weight of each channel in the path. Negativity and nonmonotonicity are commonly seen in the multi-particle Casimir entropy, the sources of which are diverse, including the geometry of the path, the types of polarization mixing, the polarizability of each particle, etc. Thermal contributions from multi-particle scatterings can be significant in the system, while the zero-temperature multi-particle scattering effects are insignificant. Limiting behaviors from a multi-particle configuration to a continuum are briefly explored.