Vacuum induced transparency and slow light phenomena in a two-level atomic ensemble controlled by a cavity
Guo Yu-Jie†a),b), Nie Wen-Jiec)
       
The real and imaginary parts of the susceptibility as a function of δ for Ng 2 = 10 κγ and κ = 0.01 γ with (a) Δ = 0.5 γ (b) Δ = −0.5 γ .