Quantum discord of the two-atom system in non-Markovian environments

The quantum discord of the two-atom system, which is in two independent Lorentzian reservoirs and in two independent Ohmic reservoirs with the Lorentz-Drude cutoff function, respectively, and the reservoirs are at zero temperature, is studied by applying the time-convolutionless master-equation method. We find that the quantum discord of the two-atom system is dependent on the characteristics of non-Markovian environments. The results show that the quantum discord can be effectively protected not only in Lorentzian reservoirs, but also in ohmic reservoirs with the Lorentz-Drude cutoff function. Finally, the physical interpretations for these results are given via the correlation function.