Weak and strong coupling regimes, vacuum Rabi splitting and two types of resonances
Centre de Physique Théorique, École Polytechnique, 91128 Palaiseau Cedex, France
Corresponding author: a email@example.com
Revised: 6 June 2006
Published online: 5 August 2006
For two discrete-level quantum systems in interaction, we follow the displacement in the complex plane of the eigen-energies of the compound system when the excited level of one of the two systems is enlarged. These new points are usually called resonances and describe mixed unstable states. This allows us to define and to calculate a critical value of the coupling constant which separates two well-known coupling regimes. These two regimes are thus described in a unified way. In the study, resonances which are usually not taken into account occur. They are studied in the large continuum case provided by the coupling of the hydrogen atom to the states of the transverse electromagnetic field in the vacuum. We justify that some of these resonances be neglected in this case.
PACS: 42.50.-p – Quantum optics / 71.36.+c – Polaritons / 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006