Entangled states nonidentical atoms

The choice of the collective states (40) as a basis leads to a complicated master equation whose physical properties are tractable only for very specific values of the parameters involved. A different choice of basis collective states is proposed here, which allows us to obtain a simple master equation of the system of two nonidentical atoms. Moreover, we will show that it is possible to create a maximally entangled state in the system of two nonidentical atoms that can be decoupled from the external environment and, at the same time, the state exhibits a strong coherent coupling with the remaining states. 

This result shows that we can relatively easily prepare two nonidentical atoms in the maximally entangled antisymmetric state. The closeness of the prepared state to the ideal one is measured by the fidelity F. Here F is equal to the obtained maximum population in the state —). For il F the fidelity of the... 

Guo and Yang [53] have analyzed spontaneous decay from two atoms initially prepared in an entangled state. They have shown that the time evolution of the population inversion, which is proportional to the intensity (87), depends on the degree of entanglement of the initial state of the system. Ficek et al. [10] have shown that in the case of two nonidentical atoms, the time evolution of the intensity 7(R, t) can exhibit quantum beats that result from the presence of correlations between the symmetric and antisymmetric states. In fact, quantum beats are present only if initially the system is in a nonmaximally entangled state, and no quantum beats are predicted for maximally entangled as well as unentangled states. 

In the section IV.B.2, we have shown that two nonidentical two-level atoms can be prepared in an arbitrary superposition of the maximally entangled antisymmetric state a) and the ground state g)... 

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