Monogamy of Quantum Discord for Multiqubit Systems

We explore the monogamy of multipartite quantum discord. In the article [Quantum Science and Technology 6, 4, 045028], Guo et al. show that quantum discord for multiqubit systems is monogamous provided that it does not increase under discard of subsystems. we illustrate that the above-mentioned preconditions are valid for a family of multiqubit states. Based on the analytical expressions of quantum discord and geometric discord of the family of states obtained in the articles [Phys. Rev. A 104, 012428] and [arXiv:2104.12344], we investigate the dynamic behavior of these under the local decoherence channel, and show that the quantum discord of even partite systems have frozen phenomenon while the odd partite systems does not exist. For geometric discord, this family of states has the frozen phenomenon under local decoherence conditions. The results show that compound noises are not necessary for sudden changes in quantum correlation, and one qubit of the quantum noise is sufficient. The research of these non-loss conditions is of great significance for understanding the evolution of quantum systems in the environment.

Automated summary

We investigate the monogamy of multipartite quantum discord. The research shows that quantum discord is monogamous for multiqubit systems if it does not increase under the discard of subsystems. We analyze a family of multiqubit states and demonstrate that the above conditions hold. By examining the dynamics of quantum discord and geometric discord under the local decoherence channel based on previous studies, we find that even-partite systems exhibit frozen phenomenon while odd-partite systems do not. In terms of geometric discord, this family of states also shows the frozen phenomenon under local decoherence conditions. The results indicate that compound noises are not necessary for sudden changes in quantum correlation, and one qubit of quantum noise is sufficient. The investigation of these non-loss conditions is of great importance for understanding the evolution of quantum systems in the environment.