Double Λ loop of four interlinked parametric interactions
Figure 4. Double Λ loop of four interlinked parametric interactions. Each of the field reservoirs b1, 2 interacts with the noninteracting parts (a, c) of the hybrid system in the Λ configuration, one wing of which is the two-mode squeezing interaction (double solid line with double-ended arrows) and the other is the beam–splitter interaction (dashed line with a single-ended arrow). The two different kinds of interactions interlink alternately.
We show that it is possible to use an atom–cavity reservoir to prepare the two-mode squeezed and entangled states of a hybrid system of an atomic ensemble and an optical field, which do not directly interact with each other. The essential mechanism is based on the combined effect of a two-mode squeezing interaction and a beam–splitter interaction between the system and the reservoir. The reservoir mechanism is important for quantum networking in that it allows an interface between a localized matter-based memory and an optical carrier of quantum information without direct interaction.