Beating 3-dB Loss Limit of Direct Reconciliation Continuous-variable Quantum Key Distribution by Using a Noiseless Linear Amplifier

2013 ◽  
Author(s):  
Yichen Zhang ◽  
Mingyang Xu ◽  
Shulong Han ◽  
Tianyi Wang ◽  
Song Yu ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Linear Amplifier

scholarly journals Continuous-Variable Quantum Key Distribution Based on Heralded Hybrid Linear Amplifier with a Local Local Oscillator

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1395
Author(s):  
Yin Li ◽  
Yijun Wang ◽  
Yun Mao ◽  
Weishao Peng ◽  
Di Jin ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Signal To Noise Ratio ◽  
Key Distribution ◽  
Local Oscillator ◽  
High Gain ◽  
Continuous Variable ◽  
Local Oscillation ◽  
Linear Amplifier ◽  
Fine Control ◽  
The Impact

An improved continuous variable quantum key distribution (CVQKD) approach based on a heralded hybrid linear amplifier (HLA) is proposed in this study, which includes an ideal deterministic linear amplifier and a probabilistic noiseless linear amplifier. The CVQKD, which is based on an amplifier, enhances the signal-to-noise ratio and provides for fine control between high gain and strong noise reduction. We focus on the impact of two types of optical amplifiers on system performance: phase sensitive amplifiers (PSA) and phase insensitive amplifiers (PIA). The results indicate that employing amplifiers, local local oscillation-based CVQKD systems can enhance key rates and communication distances. In addition, the PIA-based CVQKD system has a broader application than the PSA-based system.

scholarly journals Improving the Performance of Continuous-Variable Measurement-Device-Independent Quantum Key Distribution via a Noiseless Linear Amplifier

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1691
Author(s):  
Fan Jing ◽  
Weiqi Liu ◽  
Lingzhi Kong ◽  
Chen He
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Third Party ◽  
Secret Key ◽  
Measurement Device ◽  
Linear Amplifier ◽  
Communication Distance ◽  
Variable Measurement ◽  
Measurement Device Independent

In the continuous variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol, both Alice and Bob send quantum states to an untrusted third party, Charlie, for detection through the quantum channel. In this paper, we mainly study the performance of the CV-MDI-QKD system using the noiseless linear amplifier (NLA). The NLA is added to the output of the detector at Charlie’s side. The research results show that NLA can increase the communication distance and secret key rate of the CV-MDI-QKD protocol. Moreover, we find that the more powerful the improvement of the performance with the longer gain of NLA and the optimum gain is given under different conditions.

DISCRETELY MODULATED CONTINUOUS-VARIABLE QUANTUM KEY DISTRIBUTION WITH A NONDETERMINISTIC NOISELESS AMPLIFIER

2013 ◽  
Vol 11 (04) ◽  
pp. 1350037 ◽  
Author(s):  
JIAN FANG ◽  
YUAN LU ◽  
PENG HUANG ◽  
GUANGQIANG HE ◽  
GUIHUA ZENG
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Excess Noise ◽  
Secret Key ◽  
Transmission Distance ◽  
Linear Amplifier ◽  
Detection Stage ◽  
Maximum Transmission ◽  
Better Than

In this paper, we first study a generalized protocol of discrete modulation for continuous-variable quantum key distribution with N coherent states in a Gaussian lossy and noisy channel and investigate its performance against collective attacks. We find that discrete modulation protocols with more than eight states do not perform better than the eight-state protocol. Then, we study the improvement of this protocol by using a nondeterministic noiseless linear amplifier (NLA) on Bob's detection stage. Results indicate that a NLA with gain g can extend the maximum transmission distance by 50 log 10g2 km and can increase the maximal tolerable excess noise. With the reconciliation efficiency β, we find the gain of NLA has a maximal value defined as g max and by adjusting the gain to about βg max one can have the best improvement on secret key rate.

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