Quantum coherence versus quantum discord in two coupled semiconductor double-dot molecules via a transmission line resonator

摘要

We study the dynamics of quantum coherence and quantum correlations in two semiconductor double-dot molecules separated by a distance and indirectly coupled via a transmission line resonator. Dominant dissipation processes are considered. The numerical results show the sudden death of entanglement and the robustness of quantum discord to sudden death. Furthermore, the results indicate that the dephasing processes in our model can lead to the revival and decay of coherence and discord with the absence of entanglement for certain initial states. By observing the dynamics of coherence versus discord for different initial states, we find that the similarities and differences of coherence and discord are not only related to the dependence of discord on optimizing the measurement set, but more importantly to the coherences in individual qubits which are captured by the adopted coherence measure.