1301.3960 (Motoaki Bamba et al.)

System-reservoir coupling derived by Maxwell's boundary conditions from
weak to ultrastrong light-matter coupling regime    [PDF]

Motoaki Bamba, Tetsuo Ogawa

In the standard theory of cavity quantum electrodynamics (QED), coupling between photons inside and outside a cavity (cavity system and photonic reservoir) is given conserving the total number of photons. However, when the cavity photons (ultra)strongly interact with atoms or excitations in matters, the system-reservoir coupling must be determined from a more fundamental viewpoint. Based on the Maxwell's boundary conditions in the QED theory for dielectric media, we derive the quantum Langevin equation and input-output relation, in which the total number of polaritons (not photons) inside the cavity and photons outside is conserved.

View original: http://arxiv.org/abs/1301.3960