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Applying Gaussian quantum discord to quantum key distribution

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Chinese Science Bulletin

Abstract

In this paper, we theoretically prove that the Gaussian quantum discord state of optical field can be used to complete continuous variable (CV) quantum key distribution (QKD). The calculation shows that secret key can be distilled with a Gaussian quantum discord state against entangling cloner attack. Secret key rate is increased with the increasing of quantum discord for CV QKD with the Gaussian quantum discord state. Although the calculated results point out that secret key rate using the Gaussian quantum discord state is lower than that using squeezed state and coherent state at the same energy level, we demonstrate that the Gaussian quantum discord, which only involving quantum correlation without the existence of entanglement, may provide a new resource for realizing CV QKD.

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Acknowledgments

The author thanks for helpful discussion with Prof. Changde Xie, Kunchi Peng, Jing Zhang, and Xiaojun Jia. This work was supported by the National Basic Research Program of China (2010CB923103), the National Natural Science Foundation of China (11174188, 61121064), Shanxi Scholarship Council of China (2012-010) and Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi.

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Authors and Affiliations

  1. State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan, 030006, China

    Xiaolong Su

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  1. Xiaolong Su
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Correspondence to Xiaolong Su.

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Su, X. Applying Gaussian quantum discord to quantum key distribution. Chin. Sci. Bull. 59, 1083–1090 (2014). https://doi.org/10.1007/s11434-014-0193-x

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  • DOI: https://doi.org/10.1007/s11434-014-0193-x

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