Dissipative dynamics of quantum discord under quantum chaotic environment

We investigate the dissipative dynamics of quantum discord in a decoherence model with two initially entangled qubits in addition to a quantum kicked top. The two qubits are uncoupled during the period of our study and one of them interacts with the quantum kicked top. We find that the long-time behavior of quantum discord could be well described by the fidelity decay of the quantum kicked top; for short-time behavior, however, the phase of the amplitude of the fidelity decay is necessary to provide more specific information about the system. We have made a comparison between the quantum kicked top and the multi-mode oscillator system in describing the environment, and also compared the dynamics of the entanglement with that of quantum discord. Copyright (C) EPLA, 2010