TY - JOUR
T1 - Free space continuous-variable quantum key distribution with practical links
AU - Li, Ming
AU - Wang, Tianyi
AU - Han, Jiawei
AU - Yu, Zhongyuan
AU - Cvijetic, Milorad
AU - Ye, Han
AU - Liu, Yumin
N1 - Funding Information:
Funding. State Key Laboratory of Advanced Optical Communication Systems and Networks (2019GZKF8); National Natural Science Foundation of China (61805176); Natural Science Youth Foundation of Tianjin (17JCQNJC01800, 18JCQNJC01900).
Publisher Copyright:
© 2020 Optical Society of America
PY - 2020/12/1
Y1 - 2020/12/1
N2 - The transmittance fluctuation resulting from free space optics will impart the continuous-variable quantum key distribution (CV-QKD). In this paper, we study the CV-QKD over free space by taking practical transmittance fluctuation into account. The transmittance is modeled following the Gaussian distribution, which reflects the most realistic fluctuation since all sources of perturbation are required to be incorporated together in practice. The comprehensive comparison between the practical model and existing models in secret key rate is drawn. The numerical results reveal that the existing model of uniform distribution underestimates the impact of air link for both slow and fast fading scenarios, and the practical secret key rate will suffer severer degradation. Further, as the variance of the Gaussian model decreases, the secret key rate degrades as well. Also, a comparison between heterodyne and homodyne detection schemes is made, and we found that the heterodyne detection outperforms the homodyne detection in the secret key rate for both the slow and fast fading air quantum channels.
AB - The transmittance fluctuation resulting from free space optics will impart the continuous-variable quantum key distribution (CV-QKD). In this paper, we study the CV-QKD over free space by taking practical transmittance fluctuation into account. The transmittance is modeled following the Gaussian distribution, which reflects the most realistic fluctuation since all sources of perturbation are required to be incorporated together in practice. The comprehensive comparison between the practical model and existing models in secret key rate is drawn. The numerical results reveal that the existing model of uniform distribution underestimates the impact of air link for both slow and fast fading scenarios, and the practical secret key rate will suffer severer degradation. Further, as the variance of the Gaussian model decreases, the secret key rate degrades as well. Also, a comparison between heterodyne and homodyne detection schemes is made, and we found that the heterodyne detection outperforms the homodyne detection in the secret key rate for both the slow and fast fading air quantum channels.
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U2 - 10.1364/JOSAB.405059
DO - 10.1364/JOSAB.405059
M3 - Article
AN - SCOPUS:85096903644
VL - 37
SP - 3690
EP - 3697
JO - Journal of the Optical Society of America B: Optical Physics
JF - Journal of the Optical Society of America B: Optical Physics
SN - 0740-3224
IS - 12
ER -