“…Consider first a field in a coherent state being injected into a high Q cavity, followed by the squeezed operation, as described by S(ξ )|α = |ξ, α . The required dispersive atom-field interaction is given by the effective Hamiltonian H eff = χa † a|e e|, and after a little algebra, we can show that the evolution U ac = exp(−i a † a|e e|), combined with that determined by the squeezing operator S(ξ ) = exp(ξ * a 2 − ξa †2 ), furnishes [17,18] exp(− ia † a|e e|)|e |ξ, α = |e |ξ e −2i , α e −i , (…”