Some studies of the interaction between two two-level atoms and SU(1, 1) quantum systems
El-Shahat T M , Ismail M Kh
       

(color online) Concurrence against scaled time λt and parameter r in the absence of the qubit motion effect for the fixed value of the Bargmann index ka = kb = 1/2 and the nonnegative integer ma = mb = 1. Panel (a) for Δ/λ = 0 and panel (b) for Δ/λ = 10.