An important result from quantum optics and condensed matter physics is the use of radiation-matter interaction to produce light with specific characteristics. In this work, we study a nonstationary atom-cavity system and characterize the physical properties of the emitted light. In particular we deal with a Fabry-Perot cavity with a moving mirror which has an embedded two-level system. The study of the statistical properties is done by means of the second-order correlation function with zero delay, which allows to classify the light emitted by the physical system in three different statistical regimes (Poissonian, sub-Poissonian and super-Poissonian) depending on the relationship between the variance and the mean of the photon number distribution. Therefore, in a range of parameters for which the extraction of excitations from the quantum vacuum is evident, we find that the non-classicality of the emitted light depends strongly on the relationship between the radiation-matter coupling constant and the frequency of modulation of the length of the cavity.
In this paper, we study the statistical properties of light generated by two different types of quantum emitters embedded in an optical micro-cavity. These emitters are a single quantum dot (QD) and an artificial molecule (AM), which is made by two interacting QDs. The study of the statistical properties is done by means of the second-order correlation function, which can be calculated using the elements of the density matrix operator. Some non-Hamiltonian processes are considered such as incoherent pumping of photons, spontaneous emission, decay in leaky modes, phonon assistance to the main QD, and phonon assistance to the tunnelling mechanism. The effect of each one of those mechanisms in the emission properties of the system is analysed for a certain range of parameters. As a result, we observe that the tunnelling mechanism, as well as the phonon assistance mechanism to the main QD, are processes that can favour anti-bunching in the emitted photons. For the tunnelling phonon assistance, we find that these mechanisms attest against the non-classical character of the photons, changing its statistics by increasing the value of the second-order correlation function. However, the effect of the three mechanisms acting together on the system is a net diminish of the second-order correlation function, in comparison with the same system when all the mechanisms are turned off.