Estudo da correlação de fótons e controle óptico a partir do fenômeno da transparência eletromagneticamente induzida em cavidades para um átomo de três níveis

Abstract

The ability to produce and control single photons is one of the outstanding goals of quantum optics to pave the way towards the implementation of quantum devices. In this work, we present a theoretical study on the phenomenon of electromagnetically induced transparency combined with cavity quantum electrodynamics (CEIT) to explore the control of quantum fluctuations and photon statistics of a light beam. For this purpose, we consider a system composed of a single three-level atom in Λ configuration strongly coupled to a single quantum mode of an optical cavity. The dressed states of the system and its respective energy eigenvalues were analytically calculated through the diagonalization of the interaction hamiltonian according to the Jaynes-Cummings model. Using the formalism of the master equation for open quantum systems, we obtain the temporal evolution of the expected value of the atomic and cavity field operators, which allowed us to numerically calculate the properties of the system in the steady state, such as the transmission spectrum of the system, using different parameters. The photon statistics and the quantumness of the light emitted from the cavity were featured by calculating the equal-time second-order intensity correlation function $g^{(2)}(0)$. Additionally to the photon statistics control, which can be optically tuned via the control field intensity, with $g^{(2)}(0)$ varying from sub-Poissonian to super-Poisonian behavior, the correlation function shows two well defined sub-Poissonian regions, resulting from a single-photon and a two-photon blockade. The achievable quantum control can significantly contribute to the implementation of individual or strongly correlated photon sources or devices which attenuates or amplifies the relative intensity noise of a light beam.