Cavity QED beyond the Jaynes–Cummings model

مقال فى مجلة

Cavity QED beyond the Jaynes–Cummings model

The Jaynes–Cummings model provides a fundamental description of light–matter interactions in cavity quantum electrodynamics (QED), but its single-mode approximation becomes increasingly restrictive for nanoscale and broadband resonators. In this work, we develop a dynamical framework for cavity QED that treats the electromagnetic field without reducing it to a single cavity mode. This approach enables the analysis of spontaneous emission and light–matter interactions in subwavelength cavities with metallic boundaries, where interference between multiple electromagnetic pathways plays a central role in determining the emission dynamics. We show that the emitter decay rate can substantially exceed its free-space value under conditions of constructive interference, while, more generally, the decay rate remains close to the free-space rate. These results provide a microscopic perspective on the limitations of conventional single-mode cavity-QED descriptions and offer an explanation for the absence of strong-coupling behaviour in planar-mirror atom–cavity configurations.