Dynamics of quantum discord in two Tavis-Cummings models with classical driving fields

We investigate the dynamics of quantum discord in a system consisting of two Tavis-Cummings models, each of which contains two atoms driven by a classical field. We compare the dynamics of quantum discord for the system with that of entanglement and show that quantum discord vanishes only asymptotically although entanglement disappears suddenly during the time evolution. Furthermore, we examine the influence of the initial states and the classical field on the discord dynamics and find that the value of quantum discord can be improved by adjusting the classical driving field. Finally, the quantum discord of two atoms in dissipative cavity is also discussed.