Quantum correlations of three-qubit states driven by a classical random external field

In this paper, we exploit the notions of tripartite quantum discord D⁽³⁾, tripartite negativity N⁽³⁾, and entanglement witnesses (EWs), respectively, as a measure of quantum correlations in a model of three noninteracting qubits subject to a classical random external field. We compare the dynamics of D⁽³⁾ with that of entanglement for the initial entangled pure or mixed GHZ- and W-type states. We find that the quantum correlations dynamics depend on the input configuration of the purity of the initial states. The results show that D⁽³⁾ may be more robust than entanglement and no sudden death of the D⁽³⁾ occurs, whereas entanglement displays periodically sudden death and revivals in the regions for GHZ- and W-type states driven by a classical random external field. Furthermore, we also show that the survival partial entanglement can be detected by means of the suitable EWs. (paper)