Spectral Properties and Entropy of a Two-Level Atom in a Squeezed Vacuum with an Exponential Decay of the Driving Field

Abstract

In this thesis the spectral properties, Boltzmann-Gibbs (BG) atomic entropy and the zero-absorption isolines of a qubit in an off-resonance squeezed vacuum (SV) reservoir with an exponential decay of a coherent driving field are studied. The model Bloch equations have time-dependent coefficients and hence have no exact solutions. Two different perturbative approaches are used to solve these equations in the two limiting cases, namely, the weak and strong field cases. Having solved the Bloch equations, the instantaneous average atomic population, polarization and the BG atomic entropy are calculated in both limits of weak and strong field cases. Furthermore, the quantum regression theorem is used to obtain analytical expressions for the transient linear susceptibility in the normal vacuum (NV), thermal field (TF) and SV reservoir cases. Also, the zeroabsorption isolines are identified.