Time-evolution of entanglement and quantum discord of bipartite systems subject to 1/f^a noise

We study the dynamics of quantum correlations for two non interacting qubits initially prepared in a maximally entangled state and then coupled with an external environment characterized by a noise spectrum of the form 1/f^α. The noise spectrum is due to the interaction of each qubit with a collection of Nf classical fluctuators with fixed switching rates. We find that, depending on the characteristic of the noise spectrum considered, both entanglement and quantum discord display either a monotonic decay or the phenomena of sudden death and revivals.