Fluctuation-Induced Interaction between Randomly Charged Dielectrics

TL;DR

This paper investigates how random charge disorder in dielectrics influences fluctuation-induced forces, revealing that quenched disorder can mask Casimir forces while annealed disorder restores a universal Casimir-like interaction.

Contribution

It demonstrates the distinct effects of quenched and annealed charge disorder on the fluctuation-induced interactions between dielectric slabs.

Findings

Quenched disorder adds an inverse distance force component that can dominate at large separations.

Annealed disorder results in a universal Casimir force scaling as inverse cubic distance.

Dielectric properties influence subleading corrections in the presence of annealed disorder.

Abstract

Monopolar charge disorder effects are studied in the context of fluctuation-induced interactions between neutral dielectric slabs. It is shown that quenched bulk charge disorder gives rise to an additive contribution to the net interaction force which decays as the inverse distance between the slabs and may thus completely mask the standard Casimir--van der Waals force at large separations. By contrast, annealed (bulk or surface) charge disorder leads to a net interaction force whose large-distance behavior coincides with the universal Casimir force between perfect conductors, which scales as inverse cubic distance, and the dielectric properties enter only in subleading corrections.