Charge and Current Sum Rules in Quantum Media Coupled to Radiation

Abstract

This paper concerns the equilibrium bulk charge and current density correlation functions in quantum media, conductors and dielectrics, fully coupled to the radiation (the retarded regime). A sequence of static and time-dependent sum rules, which fix the values of certain moments of the charge and current density correlation functions, is obtained by using Rytov's fluctuational electrodynamics. A technique is developed to extract the classical and purely quantum-mechanical parts of these sum rules. The sum rules are critically tested in the classical limit and on the jellium model. A comparison is made with microscopic approaches to systems of particles interacting through Coulomb forces only (the non-retarded regime). In contrast with microscopic results, the current-current correlation function is found to be integrable in space, in both classical and quantum regimes.

19 pages, 1 figure

References in corpus (4)

• Equilibrium long-ranged charge correlations at the surface of a conductor coupled to the electromagnetic radiation
• Thermal quantum electrodynamics of nonrelativistic charged fluids
• Electric-field correlations in quantum charged fluids coupled to the radiation field
• Equilibrium long-ranged charge correlations at the interface between media coupled to the electromagnetic radiation