A hybrid system of the atomic ensemble a (red, placed within the ring cavity C1) and the cavity field c (blue, propagating along the ring cavity C2)
Figure 2. A hybrid system of the atomic ensemble a (red, placed within the ring cavity C1) and the cavity field c (blue, propagating along the ring cavity C2). The two parts of the hybrid system are not in direct interaction with each other, but coupled to the atom–cavity reservoir. The reservoir consists of the field reservoirs b1, 2 (propagating along the two cascaded cavities C1, 2) and the atomic reservoirs N1, 2 (placed respectively at the two intersections of the cavities C and C2).
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.