Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2304.03534 · Physical Review A

Mode-pairing quantum key distribution with advantage distillation

Xin Liu, Di Luo, Zhenrong Zhang, Kejin Wei

Published Jun 29, 2023• 27 citations
arXivHTMLPDF

Abstract

Mode-pairing quantum key distribution (MP-QKD) is an easy-to-implement scheme that transcends the Pirandola-Laurenza-Ottaviani-Banchi bound without using quantum repeaters. In this paper, we present an improvement of the performance of MP-QKD using an advantage distillation method. The simulation results demonstrate that the proposed scheme extends the transmission distance significantly with a channel loss exceeding 7.6 dB. Moreover, the scheme tolerates a maximum quantum bit error rate of 8.9%, which is nearly twice that of the original MP-QKD. In particular, as the system misalignment error increases, the expandable distance of the proposed scheme also increases. The proposed system is expected to promote the practical implementation of MP-QKD in a wide range of applications, particularly in scenarios involving high channel losses and system errors.

DOI
10.1103/physreva.107.062613

Related papers

Mode-pairing quantum key distribution with multi-step advantage distillation

Shizhuo Li, Xin Liu, Zhenrong Zhang +1 more

Abstract The advantage distillation (AD) technology has been proven to effectively improve the secret key rate and the communication distance of quantum key distribution (QKD). The mode-pairing quantum key distribution (MP-QKD) protocol can overcome a fundamental physical limit, known as the Pirandola–Laurenza–Ottaviani–Banchi bound, without requiring global phase-locking. In this work, we propose a method based on multi-step AD to further enhance the performance of MP-QKD. The simulation results show that, compared to one-step AD, multi-step AD achieves better performance in long-distance scenarios and can tolerate a higher quantum bit error rate. Specifically, when the difference between the communication distances from Alice and Bob to Charlie is 25 km, 50 km and 75 km, and the corresponding transmission distance exceeds 523 km, 512 km and 496 km, respectively, the secret key rate achieved by multi-step AD surpasses that of one-step AD. Our findings indicate that the proposed method can effectively promote the application of MP-QKD in scenarios with high loss and high error rate.

Chinese Physics B•Jul 28, 2025•2 citations

Asymmetric mode-pairing quantum key distribution with advantage distillation

Hai-Tao 海涛 Wang 汪, Chun Hua Zhou, Yi-Fei 宜飞 Lu 陆 +5 more

Abstract Mode-pairing quantum key distribution (MP-QKD) is an excellent scheme that can exceed the repeaterless rate-transmittance bound without complex phase locking. Nevertheless, MP-QKD usually needs to ensure that the communication distances of the two channels are equal. To address the problem, the asymmetric MP-QKD protocol is proposed. In this paper, we enhance the performance of the asymmetric MP-QKD protocol based on the advantage distillation (AD) method without modifying the quantum process. The simulation results show that the AD method can extend the communication distance by about 70 km in the case of asymmetry. And we observe that as the misalignment error increases, the AD method further increases the expandable communication distance. Our work can further enhance the robustness and promote the practical application of the asymmetric MP-QKD.

Chinese Physics B•Feb 28, 2025•4 citations

Asymmetric mode-pairing quantum key distribution

LU Zeyang, Gang Wang, Chan Li +1 more

Mode-pairing quantum key distribution (MP-QKD) can surpass the repeaterless rate-transmittance bound (Pirandola-Laurenza-Ottaviani-Banchi bound) without requiring global phase locking, exhibiting remarkable flexibility. However, MP-QKD necessitates equal communication distances in two channels, which is a challenging requirement in practical applications. To address this limitation, we extend the original MP-QKD to asymmetric cases. Our decoy-state estimation confirms that asymmetric channel transmittances and asymmetric intensities do not compromise the security of the protocol. We focus on the pulse-intensity relationship, a key factor for optimizing the performance of asymmetric MP-QKD. Unlike previous asymmetric protocols, the intensities of different bases in asymmetric MP-QKD cannot be decoupled. We introduce an optimal-pulse-intensity method, adaptable to various scenarios, to enhance key rates by calculating ideal pulse intensities. Simulation results in various representative scenarios indicate that our method effectively reduces the impact of asymmetric channel distances on MP-QKD performance, enhancing its practical applicability.

arXiv:2401.01727•Physical Review A•Jan 2, 2024•13 citations

Phase-matching quantum key distribution with advantage distillation

Rui-Qiang Wang, Chun-Mei Zhang, Zhen−Qiang Yin +5 more

Abstract Phase-matching quantum key distribution (PM-QKD) provides a promising solution to surpass the fundamental rate–distance bound without quantum repeaters. In this paper, we insert an additional advantage distillation (AD) step after quantum communication to improve the performance of PM-QKD. Simulation results show that, by splitting the raw key into blocks of only a few bits so as to identify highly correlated bit pairs, the AD method can tolerate high system misalignment errors and improve the secret key rate and transmission distance significantly, which is very promising in current PM-QKD systems.

New Journal of Physics•Jul 1, 2022•25 citations

Enhancing the performance of mode-pairing quantum key distribution by wavelength division multiplexing

Xingyu Zhou, Jiarui Hu, Jiajun Wang +3 more

Mode-pairing quantum key distribution (MP-QKD) holds great promise for the practical implementation of QKD in the near future. It combines the security advantages of measurement device independence while still being capable of breaking the Pirandola-Laurenza-Ottaviani-Banchi bound without the need for highly demanding phase-locking and phase-tracking technologies for deployment. In this work, we explore optimization strategies for MP-QKD in a wavelength-division multiplexing scenario. The simulation results reveal that incorporation of multiple wavelengths not only leads to a direct increase in key rate but also enhances the pairing efficiency by employing our novel pairing strategies among different wavelengths. As a result, our work provides a new avenue for the future application and development of MP-QKD.

Optics Express•Apr 24, 2024•12 citations

Experimental Mode-Pairing Quantum Key Distribution Surpassing the Repeaterless Bound

Likang Zhang, Wei Li, Jiawei Pan +7 more

Quantum key distribution (QKD) provides information-theoretic security for communication. The mode-pairing (MP) protocol emerges as a promising solution for long-distance QKD by eliminating the need for a global phase reference while maintaining the repeaterlike rate-loss scaling. Recent implementations have demonstrated its potential, but they either rely on costly ultrastable lasers or struggle with phase fluctuations from commercial lasers, particularly over long distances. As a result, surpassing the repeaterless bound with a practical system remains a challenge. In this work, we demonstrate a practical high-performance MP-QKD system using commercial lasers. To address phase fluctuations, we propose a frequency-tracking scheme based on fast Fourier transformation, enabling us to extend the pairing length to 2 × 10 5 pulses ( 160 μ s ). We propose a model to carefully analyze the phase noise and optimize the system parameters. Our system achieves an optimal secret key rate of 47.8 bit / s over 403 km of standard fiber (76.5 dB loss), exceeding the repeaterless bound by a factor of 2.92. Furthermore, we compare MP-QKD and twin-field QKD under various practical conditions and clarify the distinct application scenarios of the two protocols. These results confirm the feasibility of MP-QKD using cost-effective commercial technologies, paving the way for scalable quantum communication networks.

Physical Review X•May 2, 2025•23 citations
Mode-pairing quantum key distribution (MP-QKD) is an easy-to-implement scheme that transcends the Pirandola-Laurenza-Ottaviani-Banchi bound without using quantum repeaters. In this paper, we present an improvement of the performance of MP-QKD using an advantage distillation method. The simulation results demonstrate that the proposed scheme extends the transmission distance significantly with a channel loss exceeding 7.6 dB. Moreover, the scheme tolerates a maximum quantum bit error rate of 8.9%, which is nearly twice that of the original MP-QKD. In particular, as the system misalignment error increases, the expandable distance of the proposed scheme also increases. The proposed system is expected to promote the practical implementation of MP-QKD in a wide range of applications, particularly in scenarios involving high channel losses and system errors.
Abstract The advantage distillation (AD) technology has been proven to effectively improve the secret key rate and the communication distance of quantum key distribution (QKD). The mode-pairing quantum key distribution (MP-QKD) protocol can overcome a fundamental physical limit, known as the Pirandola–Laurenza–Ottaviani–Banchi bound, without requiring global phase-locking. In this work, we propose a method based on multi-step AD to further enhance the performance of MP-QKD. The simulation results show that, compared to one-step AD, multi-step AD achieves better performance in long-distance scenarios and can tolerate a higher quantum bit error rate. Specifically, when the difference between the communication distances from Alice and Bob to Charlie is 25 km, 50 km and 75 km, and the corresponding transmission distance exceeds 523 km, 512 km and 496 km, respectively, the secret key rate achieved by multi-step AD surpasses that of one-step AD. Our findings indicate that the proposed method can effectively promote the application of MP-QKD in scenarios with high loss and high error rate.
Abstract Mode-pairing quantum key distribution (MP-QKD) is an excellent scheme that can exceed the repeaterless rate-transmittance bound without complex phase locking. Nevertheless, MP-QKD usually needs to ensure that the communication distances of the two channels are equal. To address the problem, the asymmetric MP-QKD protocol is proposed. In this paper, we enhance the performance of the asymmetric MP-QKD protocol based on the advantage distillation (AD) method without modifying the quantum process. The simulation results show that the AD method can extend the communication distance by about 70 km in the case of asymmetry. And we observe that as the misalignment error increases, the AD method further increases the expandable communication distance. Our work can further enhance the robustness and promote the practical application of the asymmetric MP-QKD.
Mode-pairing quantum key distribution (MP-QKD) can surpass the repeaterless rate-transmittance bound (Pirandola-Laurenza-Ottaviani-Banchi bound) without requiring global phase locking, exhibiting remarkable flexibility. However, MP-QKD necessitates equal communication distances in two channels, which is a challenging requirement in practical applications. To address this limitation, we extend the original MP-QKD to asymmetric cases. Our decoy-state estimation confirms that asymmetric channel transmittances and asymmetric intensities do not compromise the security of the protocol. We focus on the pulse-intensity relationship, a key factor for optimizing the performance of asymmetric MP-QKD. Unlike previous asymmetric protocols, the intensities of different bases in asymmetric MP-QKD cannot be decoupled. We introduce an optimal-pulse-intensity method, adaptable to various scenarios, to enhance key rates by calculating ideal pulse intensities. Simulation results in various representative scenarios indicate that our method effectively reduces the impact of asymmetric channel distances on MP-QKD performance, enhancing its practical applicability.
Abstract Phase-matching quantum key distribution (PM-QKD) provides a promising solution to surpass the fundamental rate–distance bound without quantum repeaters. In this paper, we insert an additional advantage distillation (AD) step after quantum communication to improve the performance of PM-QKD. Simulation results show that, by splitting the raw key into blocks of only a few bits so as to identify highly correlated bit pairs, the AD method can tolerate high system misalignment errors and improve the secret key rate and transmission distance significantly, which is very promising in current PM-QKD systems.
Mode-pairing quantum key distribution (MP-QKD) holds great promise for the practical implementation of QKD in the near future. It combines the security advantages of measurement device independence while still being capable of breaking the Pirandola-Laurenza-Ottaviani-Banchi bound without the need for highly demanding phase-locking and phase-tracking technologies for deployment. In this work, we explore optimization strategies for MP-QKD in a wavelength-division multiplexing scenario. The simulation results reveal that incorporation of multiple wavelengths not only leads to a direct increase in key rate but also enhances the pairing efficiency by employing our novel pairing strategies among different wavelengths. As a result, our work provides a new avenue for the future application and development of MP-QKD.
Quantum key distribution (QKD) provides information-theoretic security for communication. The mode-pairing (MP) protocol emerges as a promising solution for long-distance QKD by eliminating the need for a global phase reference while maintaining the repeaterlike rate-loss scaling. Recent implementations have demonstrated its potential, but they either rely on costly ultrastable lasers or struggle with phase fluctuations from commercial lasers, particularly over long distances. As a result, surpassing the repeaterless bound with a practical system remains a challenge. In this work, we demonstrate a practical high-performance MP-QKD system using commercial lasers. To address phase fluctuations, we propose a frequency-tracking scheme based on fast Fourier transformation, enabling us to extend the pairing length to 2 × 10 5 pulses ( 160 μ s ). We propose a model to carefully analyze the phase noise and optimize the system parameters. Our system achieves an optimal secret key rate of 47.8 bit / s over 403 km of standard fiber (76.5 dB loss), exceeding the repeaterless bound by a factor of 2.92. Furthermore, we compare MP-QKD and twin-field QKD under various practical conditions and clarify the distinct application scenarios of the two protocols. These results confirm the feasibility of MP-QKD using cost-effective commercial technologies, paving the way for scalable quantum communication networks.