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Geometric measure of quantum discord with weak measurements

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Abstract

Super quantum discord based on weak measurements was introduced by Singh and Pati (Ann Phys 343:141–152, 2014). We propose a geometric way of quantifying quantum discord with weak measurements. It is shown that this geometric measure of quantum discord with weak measurements (GQDW) is linearly dependent on geometric measure of quantum discord (Dakic et al. in Phys Rev Lett 105:190502, 2010) and only captures partial quantumness of the states. It is found that the quantum correlation can be extracted by a sequence of infinitesimal weak measurements. Finally, the level surfaces of GQDW for Bell-diagonal states are depicted and the results are demonstrated by explicit example.

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Acknowledgments

The authors would like to thank the editor and anonymous referees for their valuable suggestions. This research was supported by the grants from the Natural Science Foundation Of China (11401588), (11571220), (11105226); the Fundamental Research Funds for the Central Universities No.(15CX02075A); Research Award Fund for outstanding young scientists of Shandong Province No.(BS2012DX045).

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Correspondence to Qing-Wen Wang.

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Li, L., Wang, QW., Shen, SQ. et al. Geometric measure of quantum discord with weak measurements. Quantum Inf Process 15, 291–300 (2016). https://doi.org/10.1007/s11128-015-1184-9

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  • DOI: https://doi.org/10.1007/s11128-015-1184-9

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