title: Steady State Entanglement in Cavity QED.
abstract: We investigate steady state entanglement in an open quantum system, specifically a single atom in a driven optical cavity with cavity loss and spontaneous emission. The system reaches a steady pure state when driven very weakly. Under these conditions, there is an optimal value for atom-field coupling to maximize entanglement, as larger coupling favors a loss port due to the cavity enhanced spontaneous emission. We address ways to implement measurements of the entanglement and find that normalized cross-correlation functions are indicators of the entanglement in the system. The equal time intensity-field cross correlation between the transmitted field of the cavity and the fluorescence intensity is proportional to the entanglement of formation for weak driving fields.
authors.forename: P R
authors.initials: PR
authors.lastname: Rice
authors.forename: J
authors.initials: J
authors.lastname: Gea-Banacloche
authors.forename: M L
authors.initials: ML
authors.lastname: Terraciano
authors.forename: D L
authors.initials: DL
authors.lastname: Freimund
authors.forename: L A
authors.initials: LA
authors.lastname: Orozco