Fig. 1. Three-level atoms are in a Λ configuration, and the classical radiation fields have two different frequencies (right panel). Experimentally, such atomic systems consist of a binary mixture of BEC atoms, which are distributed in two hyperfine states and are transferred between them by the action of radiation fields^[18] (left panel).

Fig. 2. Effect of initial state on the time evolution of population inversion for N=N¯=10 and G = 100B with scaled time τ = Bt.

Fig. 3. Effect of G on the time evolution of population inversion in the case of number state versus the scaled time τ = Bt with N = 20.

Fig. 4. Evolution of population inversion for the number state (dash lines) and perturbed state (solid lines) against the scaled time τ = At, when B = 0.2A for different numbers of atoms in the system. The parity of number of atoms considerably affects the behavior of population inversion. The even parity leads to MQSTS phenomenon.

Fig. 5. Comparison between the results of the perturbation method and numerical solution of the Schrödinger equation for N=10, B=A=100q, and τ=At.