A Quantum Treatment of Spontaneous Emission Without Photons

Abstract

The question whether it is possible to account for spontaneous emission of electromagnetic radiation from atoms without quantum electrodynamics has lately been the subject of further discussion.[1–5] In a recent article Nesbet[5] has considered an approach to the problem that differs substantially from the neoclassical approach of Jaynes and his co-workers.[1–3] In this theory the electromagnetic field is expressed explicitly in terms of its sources, which are quantized, and it obeys the algebra of the sources, while the concept of the free boson field is discarded altogether. Although he has referred to it as ‘semi-quantized radiation theory’, the theory is actually a fully quantized one, in the sense that no c-number currents or fields appear. When the rate of energy flow into the far electromagnetic field written in normal order is equated to the rate of energy loss of a two-level atom, Nesbet’s theory apparently leads to exponential decay of the atomic energy.[5,6]

This work was supported by the Air Force Office of Scientific Research and by the National Science Foundation.