Zero-Absorption Isolines and Probe Spectra of a Qubit in an Off-Resonance Squeezed Vacuum with Decaying Weak Field
Shoukry S. Hassan, O. M. Frege and Mohamed M. Hassan
Analytical expressions for the absorption and dispersion spectra of a weak signal field probing the system of a weakly driven 2-level atom in a broadband squeezed vacuum (SV) with an exponentially decaying of the driving field are derived. The atomic transition frequency and the central frequency of both the SV and the driving field are assumed to be different. The contour plots of the zero absorption spectrum, called zero-absorption isolines, in the (Δ, Ω)-plane are found to be: (i) symmetric with respect to the atomic detuning frequency parameter Δfor resonant probe field, and (ii) asymmetric with respect to Δ for probe frequency detuned at the Rabi-side frequency Ω of the driving field. The largest set of points, where absorption is zero, in the (Δ, Ω)-plane depends on the phase and the SV detuning parameters.
Keywords: Zero-absorption isolines, absorption and dispersion spectra, squeezed vacuum