Journal of Physics Condensed Matter
Signatures of the electromagnetic field quantization in the nonlinear optical response of excitons
Salvatore Savasta, R. Girlanda
Abstract
We present a fully quantum mechanical theory for an interacting system of photonsand Coulomb correlated electrons and holes in a semiconductor, using a pertubation series in theexciting laser field. The theory provides microscopic descriptions of nonlinear optical processes insemiconductors related to the electromagnetic field quantization. As an application of the theorywe show that it is possible to transfer the exciton exciton Coulomb correlation to photons, thusproducing pairs of near-gap photons with a high degree of quantum entanglement. The photon pairsemerge from the spontaneous optical decay of biexcitons into two polaritons. The pair intensitycorrelations, calculated in the lowdensity limit for a CuCl slab and for semiconductor microcavities,exhibit quantum features which can be observed by coincidence detection.