Equation Icon  [ ] [ ] ˆac(Ω ),ˆa†c(Ω′) = ˆas(Ω),ˆa†s(Ω ′) = 2π Ω-δ(Ω − Ω′), (53 ) [ ] [ ] ω0 ˆac(Ω ),ˆa†(Ω′) = ˆa†(Ω),ˆas(Ω ′) = 2πiδ(Ω − Ω′), (54 ) s c