QED for a Fibrillar Medium of Two-Level Atoms

TL;DR

This paper develops a quantum electrodynamics framework for a fibrillar medium of two-level atoms, analyzing dispersion relations, dielectric properties, and renormalization effects with comparisons to established approximations.

Contribution

It introduces a perturbative quantum field theory approach for a fibrillar atomic medium, including one-loop corrections and renormalization group analysis.

Findings

Renormalization group equations show screening of two-level splitting at high energies

One-loop corrections modify polariton dispersion relations and dielectric constant

Results align with known approximations like the rotating wave approximation

Abstract

We consider a fibrillar medium with a continuous distribution of two-level atoms coupled to quantized electromagnetic fields. Perturbation theory is developed based on the current algebra satisfied by the atomic operators. The one-loop corrections to the dispersion relation for the polaritons and the dielectric constant are computed. Renormalization group equations are derived which demonstrate a screening of the two-level splitting at higher energies. Our results are compared with known results in the slowly varying envelope and rotating wave approximations. We also discuss the quantum sine-Gordon theory as an approximate theory.