Atomic level structures for the present scheme XuQing HuXiangming 2013 <p><strong>Figure 3.</strong> Atomic level structures for the present scheme. (a) Three-level atom for the atomic mode <em>a</em>, which is in the Raman resonance with the field reservoirs <em>b</em><sub>1, 2</sub>. (b) Two-level atom for the atomic reservoir <em>N</em><sub>1</sub>, which is coupled to the cavity mode <em>c</em> and the field reservoir <em>b</em><sub>1</sub> through dispersive resonance. (c) Three-level atom for the atomic reservoir <em>N</em><sub>2</sub>, which is in the dispersive resonance with the cavity mode <em>c</em> and the field reservoir <em>b</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>