We calculate the single and two photon emission from a cavity containing quantum dot incoherently pumped. Results for correlation functions and the entanglement visibility of linearly polarized photons are presented.
We study the photon emission from a quantum dot embedded in a microcavity. Incoherent pumping of its excitons and biexciton provokes the emission of leaky and cavity modes. By solving a master equation we obtain the correlation functions required to compute the spectrum and the relative efficiency among the emission of pairs and single photons. A quantum regime appears for low pumping and large rate of emission. By means of a post-selection process, a two beams experiment with different linear polarizations could be performed producing a large polarization entanglement visibility precisely in the quantum regime.
We theoretically investigate the optical response of a quantum dot, embedded in a microcavity and incoherently excited by pulsed pumping. The exciton and biexciton transition are off-resonantly coupled with the left- and right-polarized mode of the cavity, while the two-photon resonance condition is fulfilled. Rich behaviours are shown to occur in the time dependence of the second-order correlation functions which refer to counter-polarized photons. The corresponding time-averaged quantities, which are accessible to experiments, confirm that such a dot-cavity system behaves as a good emitter of single, polarization-correlated photon pairs.
Entanglement and lasing of two quantum dots in a microcavity are investigated in the steady state achieved under a continuous incoherent pumping. Lasing is favored in the case of independent pumping of the dots, i.e., when an electron-hole pair which reaches one dot does not affect the other. In this case, having two dots allows a qualitative enhancement of the lasing emission as compared to the single dot case. On the other hand, when the two dots share the excitation bath, giving rise to a quantum uncertainty of the final state of the excitation, entanglement properties are enhanced in detriment of the photon emission. Slightly different couplings between the dots and the cavity induce good singlet-state population. This allows good entanglement in a system pumped continuously and incoherently.