 Jaynes–Cummings model

The Jaynes-Cummings model couples a two-level atom to one quantized oscillator mode throughThe first term excites the atom while annihilating one field quantum; the second performs the Hermitian-conjugate process.

The Jaynes–Cummings model is a fundamental theoretical framework in quantum optics and quantum information theory. It describes the interaction between a two-level atom (often referred to as a qubit or quantum bit) and a single mode of an electromagnetic field, typically modeled as a harmonic oscillator. The model captures essential features of light-matter interactions, particularly in the context of cavity quantum electrodynamics (QED).