Thermodynamic QED Coherence in Condensed Matter: Microscopic Basis of Thermal Superradiance

TL;DR

This paper investigates the microscopic foundations of thermal superradiance in condensed matter, addressing theoretical debates and establishing the physical plausibility of superradiant phases through thermodynamic and electromagnetic coherence principles.

Contribution

It provides a microscopic basis for thermal superradiance in condensed matter, clarifying the role of electromagnetic coherence and resolving theoretical concerns about diamagnetic effects.

Findings

Thermal superradiant phases are theoretically supported in condensed matter.

Landau-Lifshitz theorem rules out diaelectric correlations in these systems.

Microscopic analysis confirms the physical reality of superradiant coherence.

Abstract

Electromagnetic superradiant field coherence exists in a condensed matter system if the electromagnetic field oscillators undergo a mean displacement. Transitions into thermal states with ordered superradiant phases have been shown to theoretically exist in Dicke-Preparata models. The theoretical validity of these models for condensed matter has been called into question due to non-relativistic diamagnetic terms in the electronic Hamiltonian. The microscopic bases of Dicke-Preparata thermal superradiance for realistic macroscopic systems are explored in this work. The impossibility of diaelectric correlations in condensed matter systems (via the Landau-Lifshitz theorem) provides a strong theoretical basis for understanding the physical reality of condensed matter thermodynamic superradiant phases.