Geometric quantum discord and non-Markovianity of structured reservoirs

The reservoir memory effects can lead to information backflow and recurrence of the previously lost quantum correlations. We establish connections between the direction of information flow and variation of the geometric quantum discords (GQDs) measured respectively by the trace distance, the Hellinger distance, and the Bures distance for two qubits subjecting to the bosonic structured reservoirs, and unveil their dependence on a factor whose derivative signifies the (non-)Markovianity of the dynamics. By considering the reservoirs with Lorentzian and Ohmic-like spectra, we further demonstrated that the non-Markovianity induced by the backflow of information from the reservoirs to the system enhances the GQDs in most of the parameter regions. This highlights the potential of non-Markovianity as a resource for protecting the GQDs. -- Highlights: •Dependence of GQDs on a factor determined by spectrum of the structured reservoir. •Connection between the direction of information flow and variation of the GQDs. •Non-Markovianity with the backflow of information enhances GQDs in a wide region. •The GQDs are enhanced with the information loss in a very narrow region.