Phase dependence of the variance 〈(δX₊)²〉 for s = 5, q = (0, 0.2, 0.5, 1, 5, 10)

Figure 7. Phase dependence of the variance 〈(δX₊)²〉 for s = 5, q = (0, 0.2, 0.5, 1, 5, 10). (a) Φ = 0 (the same as in figure 5(d) and given for the sake of comparison), (b) \Phi =\pm \frac{\pi }{4}, (c) \Phi =\pm \frac{\pi }{2} and (d) Φ = π. Different from the case in figure 6, the present case has squeezing and entanglement even when Φ = π.

Abstract

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.