<p><strong>Figure 1.</strong> Three different systems of two noninteracting parts. A composite reservoir (two grey circular plates) mediates between the two parts of the system. A blue plate stands for a cavity field while a red plate represents an atomic ensemble. A line denotes the system–reservoir interaction. (a) A dual atomic reservoir enters between two cavity fields [<a href="http://iopscience.iop.org/0953-4075/46/18/185501/article#jpb474929bib27" target="_blank">27</a>]. (b) A dual cavity reservoir is used between two atomic ensembles [<a href="http://iopscience.iop.org/0953-4075/46/18/185501/article#jpb474929bib32" target="_blank">32</a>]. (c) An atom–cavity reservoir mediates between an atomic ensemble and a cavity field. The last scheme has not been explored yet and will be addressed in the present work.</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
