Non-classical properties of the e.m. near field of an atom in spontaneous light emission

TL;DR

This paper investigates the non-classical properties of the electromagnetic near field emitted by an atom during spontaneous light emission, focusing on the role of the longitudinal electric field using Glauber's correlation and Green functions.

Contribution

It introduces a detailed analysis of the longitudinal electric field's role in spontaneous emission, extending the understanding beyond traditional photonic degrees of freedom.

Findings

Identification of non-classical features in the near field

Clarification of the longitudinal electric field's influence

Enhanced understanding of causal behavior in spontaneous emission

Abstract

We use Glauber's correlation function as well as the Green functions formalism to investigate, in the case of a dipolar atomic transition, the causal behaviour of the spontaneously emitted electromagnetic field, in the A.p coupling. This brings us to examine the role played by the longitudinal electric field, which is not described in terms of photonic (transverse) degrees of freedom.