Controllable quantum correlations of two-photon states generated using classically driven three-level atoms

摘要

We investigate the dynamics of two-photon correlations generated by theinteraction of a three-level atom in the $\Xi$, $\Lambda$ or V configuration,with two classical external driving fields, under the rotating-waveapproximation, in the presence of level decays. Using the example of a rubidiumatom in each configuration, with field strengths validating the single-photonapproximation, we compute measurement based correlations, such as measurementinduced disturbance (MID), quantum discord (QD), and quantum work deficit (WD),and compare the results with that of quantum entanglement (concurrence).Certain correlation properties observed are generic, model independent andconsistent with known results, e.g., MID is an upper bound on QD, QD and WD aremonotonic, and the generic correlation behavior is strongly affected by thepurity of the photon states. We observe that the qualitative hierarchy,monotonicity and steady-state behavior of the correlations can be controlled bythe choice of parameters such as atomic decay constants and external drivingfield strengths. We point out how particular configurations are better suitedat generating monotonic correlations in specific regimes and how thesteady-state correlation behavior and hierarchy are affected by the populationdynamics of the density matrix for different parameters. The possibility ofusing well studied quantum optical systems such as the three-level atom togenerate, characterize and parametrically control mixed state quantumcorrelations establishes an important step in the direction of theirimplementation in quantum information tasks.