Partial entangling power for the Jaynes–Cummings model

Partial entangling power provides the average amount of entanglement produced by a d1 × d2 bipartite unitary operator. The average is done over the initial distribution of the states of one of the subsystems. In this paper, we extend the expression of the partial entangling power to the case that d1 is finite and d2 is arbitrary. In particular, we give an explicit expression of partial entangling power for the 2 × ∞ system. The expression can be well applicable to the Jaynes–Cummings model (JCM). The results can recover the well-known phenomenon in the JCM. We explicitly discuss its behaviour in the large detuning case and at the resonance case. Comparing the two cases, we find that it is easier for the JCM in the large detuning case to reach and maintain its maximum entangling power, while for the JCM at resonance, the achievable maximum entangling power is larger. In addition, the time average partial entangling power is also discussed.