A study on quantum discord sudden changes

Lucas C. Céleri, Jonas Maziero

Liang Qiu, Gang Tang, Xianqing Yang +3 more

L. H. Wu, A. C. Yang, W. W. Cheng

Bai, Mei, Xiang-Yu Qin, Xue‐Qun Yan

We study the peculiar dynamics of two qubits quantum discord with a sudden change in behavior. It is widely agreed in the literature nowadays that environment induce sudden change behavior of quantum discord. We explore the sudden change phenomenon under the action of local-independent environments, considering the discord of two-qubit which is obtained by means of the weak measurements on one of the two-qubit. It is shown that the sudden change phenomenon does not appear under weak measurements. We find that the quantum discord with weak measurements decays in a monotonic fashion, and show that quantum discord might exhibit a sudden change only for the strong (projective) measurement. We believe that environment is not the main role of the sudden change, but the quantum correlation itself is.

Xiaokun Yan, Guo‐Hua Liu, J. Chee

We study quantum discord by using the geometric measure of quantum discord for a class of quantum states with bound entanglement. It is found that there exists a nondynamic sudden change in quantum discord accompanying transition from bound entanglement to free entanglement. The calculations presented here should be of interest to the continuing efforts to understand sudden transition of quantum correlations.

Vlatko Vedral