A hybrid system of the atomic ensemble <em>a</em> (red, placed within the ring cavity <em>C</em><sub>1</sub>) and the cavity field <em>c</em> (blue, propagating along the ring cavity <em>C</em><sub>2</sub>)
<p><strong>Figure 2.</strong> A hybrid system of the atomic ensemble <em>a</em> (red, placed within the ring cavity <em>C</em><sub>1</sub>) and the cavity field <em>c</em> (blue, propagating along the ring cavity <em>C</em><sub>2</sub>). 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 <em>b</em><sub>1, 2</sub> (propagating along the two cascaded cavities <em>C</em><sub>1, 2</sub>) and the atomic reservoirs <em>N</em><sub>1, 2</sub> (placed respectively at the two intersections of the cavities <em>C</em> and <em>C</em><sub>2</sub>).</p> <p><strong>Abstract</strong></p> <p>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.</p
