arXiv:1301.3960 · Physical Review A

System-environment coupling derived by Maxwell's boundary conditions from the weak to the ultrastrong light-matter-coupling regime

Motoaki Bamba, Tetsuo Ogawa

Published Jul 9, 2013• 27 citations

Abstract

In the standard theory of cavity quantum electrodynamics (QED), coupling between photons inside and outside a cavity (cavity system and environment) is given conserving the total number of photons. However, when the cavity photons (ultrastrongly) interact with atoms or excitations in matters, the system-environment 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.

DOI: 10.1103/physreva.88.013814

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Comment on “System-environment coupling derived by Maxwell's boundary conditions from the weak to the ultrastrong light-matter-coupling regime”

Simone De Liberato

In a recent paper, Bamba and Ogawa [Phys. Rev. A 88, 013814 (2013)] developed a microscopic model describing a photonic cavity coupled to an excitonlike resonance. One of the results they obtained studying such a model is that, in the ultrastrong coupling regime, dissipation rates calculated applying the rotating-wave approximation on the system-environment coupling qualitatively differ from the ones calculated using a microscopic theory based on the quantum electrodynamics for dielectric media. Here I show that this result is an artifact, caused by an inconsistent application of the rotating-wave approximation and by an unphysical parameter choice.

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