Phase dependence of the variance 〈(δ<em>X</em>₊)²〉 for <em>s</em> = 1, <em>q</em> = (0, 0.2, 0.5, 1, 5, 10)

<p><strong>Figure 6.</strong> Phase dependence of the variance 〈(δ<em>X</em>₊)²〉 for <em>s</em> = 1, <em>q</em> = (0, 0.2, 0.5, 1, 5, 10). (a) Φ = 0 (the same as in figure <a href="http://iopscience.iop.org/0953-4075/46/18/185501/article#jpb474929f5" target="_blank">5</a>(b) and given for the sake of comparison), (b) \Phi =\pm \frac{\pi }{12}, (c) \Phi =\pm \frac{\pi }{6} and (d) \Phi =\pm \frac{\pi }{4}. The correlation degrades as the phase increases from zero. Squeezing and entanglement tend to vanish as the phase approaches \Phi =\pm \frac{\pi }{2} (not shown here).</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.