The recent first-principles derivation of Langevin-Bloch equations of motion for near-resonant atoms embedded in a linear dielectric host leads to a clear, direct physical reinterpretation of fundamental physical principles as applied to one of the most basic problems of quantum mechanics: the renormalization of the spontaneous emission rate of an atom in a dielectric host. Here we show the role of the Lorentz local field, the fluctuation-dissipation theorem, the wave number and wave vector, the density of states, Fermi’s golden rule, the electromagnetic energy density, canonical quantization, and the classical constitutive relations in this context.

• Received 23 June 2000

DOI:https://doi.org/10.1103/PhysRevA.63.013801