Experimental demonstration of scalable quantum cryptographic conferencing

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhu, Haotao, Li, Zhenhua, Zhao, Shuai, Lyu, Xiaodan, Ru, Shihao, Huang, Yizhi, Xu, Zitong, Qu, Rui, Gao, Weibo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908697033179136
author Zhu, Haotao
Li, Zhenhua
Zhao, Shuai
Lyu, Xiaodan
Ru, Shihao
Huang, Yizhi
Xu, Zitong
Qu, Rui
Gao, Weibo
author_facet Zhu, Haotao
Li, Zhenhua
Zhao, Shuai
Lyu, Xiaodan
Ru, Shihao
Huang, Yizhi
Xu, Zitong
Qu, Rui
Gao, Weibo
contents Quantum network enables a variety of quantum information processing tasks, where multi-user quantum communication is one of the important objectives. Quantum cryptographic conferencing serves as an essential solution to establish secure keys to realize secure multi-user communications. However, existing QCC implementations have been fundamentally limited by the low probability of multi-user coincidence detection to measure or construct the Greenberger-Horne-Zeilinger (GHZ) entangled state. In this work, we report the experimental realization of QCC eliminating the need for coincidence detection, where the GHZ state is constructed by correlating detection events occurring within the coherence time, thereby greatly enhancing the success probability of GHZ-state measurement. Meanwhile, to establish and maintain high-visibility GHZ measurement among three independent users, we developed a three-party phase compensation scheme combined with precise temporal and polarization alignment within a time-bin-phase encoding framework. Furthermore, we designed an efficient pairing strategy to simplify subsequent data processing and enhance processing efficiency. Based on these techniques, we successfully performed QCC experiments over total channel losses of 66.3 dB, corresponding to 331.5 km of commercial fiber (0.2 dB/km), achieving secure key rates of 5.4 bit/s, whereas previous QCC experiments have been limited to 100 km. The results surpass the multi-user repeaterless bound in quantum networks, establishing a new regime of scalable, multi-user quantum communication and paving the way for metropolitan quantum networks.
format Preprint
id arxiv_https___arxiv_org_abs_2512_06661
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Experimental demonstration of scalable quantum cryptographic conferencing
Zhu, Haotao
Li, Zhenhua
Zhao, Shuai
Lyu, Xiaodan
Ru, Shihao
Huang, Yizhi
Xu, Zitong
Qu, Rui
Gao, Weibo
Quantum Physics
Quantum network enables a variety of quantum information processing tasks, where multi-user quantum communication is one of the important objectives. Quantum cryptographic conferencing serves as an essential solution to establish secure keys to realize secure multi-user communications. However, existing QCC implementations have been fundamentally limited by the low probability of multi-user coincidence detection to measure or construct the Greenberger-Horne-Zeilinger (GHZ) entangled state. In this work, we report the experimental realization of QCC eliminating the need for coincidence detection, where the GHZ state is constructed by correlating detection events occurring within the coherence time, thereby greatly enhancing the success probability of GHZ-state measurement. Meanwhile, to establish and maintain high-visibility GHZ measurement among three independent users, we developed a three-party phase compensation scheme combined with precise temporal and polarization alignment within a time-bin-phase encoding framework. Furthermore, we designed an efficient pairing strategy to simplify subsequent data processing and enhance processing efficiency. Based on these techniques, we successfully performed QCC experiments over total channel losses of 66.3 dB, corresponding to 331.5 km of commercial fiber (0.2 dB/km), achieving secure key rates of 5.4 bit/s, whereas previous QCC experiments have been limited to 100 km. The results surpass the multi-user repeaterless bound in quantum networks, establishing a new regime of scalable, multi-user quantum communication and paving the way for metropolitan quantum networks.
title Experimental demonstration of scalable quantum cryptographic conferencing
topic Quantum Physics
url https://arxiv.org/abs/2512.06661