Approximate phase-coherent states and their generation
Christopher C. Gerry, Trung Bui · Physical Review A · 2009
We show that phase-coherent states of a single-mode quantized electromagnetic field are well approximated by certain superpositions of the squeezed vacuum and one-photon states. We further show that the squeezed vacuum and one-photon states can be understood, approximately, as superpositions of phase-coherent states. Our approximate phase-coherent states may be generated by a degenerate parametric down-converter acting on a prepared input state of the form $|0⟩+\ensuremath{\alpha}|1⟩$. The input superposition state itself can be prepared from a coherent state $|\ensuremath{\alpha}⟩$ by a quantum scissors device.