1
|
Yang KX, Mao YL, Chen H, Dong X, Zhu J, Wu J, Li ZD. Experimental Measurement-Device-Independent Quantum Conference Key Agreement. PHYSICAL REVIEW LETTERS 2024; 133:210803. [PMID: 39642485 DOI: 10.1103/physrevlett.133.210803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 10/21/2024] [Indexed: 12/09/2024]
Abstract
Quantum networks aim to enable quantum information tasks among multiple parties. Quantum conference key agreement (QCKA) is a typical task in quantum networks, which distributes information-theoretically secure keys among multiple users. However, QCKA relying on directly distributing Greenberger-Horne-Zeilinger (GHZ) states over long distances faces significant challenges due to the fragility of these states. Measurement-device-independent QCKA (MDI-QCKA) based on distributing the postselected GHZ entanglement can address this issue and eliminate all loopholes in detection side channels. Here, by developing three-photon GHZ interference technology with high visibility among three independent coherent sources, we realized the first MDI-QCKA experiment over a 60 km fiber link, achieving a secret key rate of 45.5 bits/s. Our result represents a significant step towards practical long-distance QCKA using realistic devices. Moreover, the technology we developed opens the way to future multiparty quantum communications in quantum networks.
Collapse
Affiliation(s)
- Kui-Xing Yang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology, Center for Intense Laser Application Technology, and College of Engineering Physics, Shenzhen Technology University, Shenzhen 518118, China
- International Quantum Academy, Shenzhen 518048, China
| | | | | | | | | | | | | |
Collapse
|
2
|
Yu M, Li X, Chu Y, Mera B, Ünal FN, Yang P, Liu Y, Goldman N, Cai J. Experimental demonstration of topological bounds in quantum metrology. Natl Sci Rev 2024; 11:nwae065. [PMID: 39301073 PMCID: PMC11409888 DOI: 10.1093/nsr/nwae065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 12/22/2023] [Accepted: 02/25/2024] [Indexed: 09/22/2024] Open
Abstract
Quantum metrology is deeply connected to quantum geometry, through the fundamental notion of quantum Fisher information. Inspired by advances in topological matter, it was recently suggested that the Berry curvature and Chern numbers of band structures can dictate strict lower bounds on metrological properties, hence establishing a strong connection between topology and quantum metrology. In this work, we provide a first experimental verification of such topological bounds, by performing optimal quantum multi-parameter estimation and achieving the best possible measurement precision. By emulating the band structure of a Chern insulator, we experimentally determine the metrological potential across a topological phase transition, and demonstrate strong enhancement in the topologically non-trivial regime. Our work opens the door to metrological applications empowered by topology, with potential implications for quantum many-body systems.
Collapse
Affiliation(s)
- Min Yu
- School of Physics, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiangbei Li
- School of Physics, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yaoming Chu
- School of Physics, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bruno Mera
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
| | - F Nur Ünal
- TCM Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
| | - Pengcheng Yang
- School of Physics, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yu Liu
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
- Institut für Theoretische Physik and IQST, Universität Ulm, Ulm D-89081 Germany
| | - Nathan Goldman
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Brussels B-1050, Belgium
- Laboratoire Kastler Brossel, Collège de France, Paris 75005, France
| | - Jianming Cai
- School of Physics, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- International Joint Laboratory on Quantum Sensing and Quantum Metrology, Huazhong University of Science and Technology, Wuhan 430074, China
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| |
Collapse
|
3
|
Lee D, Shin W, Park S, Kim J, Shin H. NOON-state interference in the frequency domain. LIGHT, SCIENCE & APPLICATIONS 2024; 13:90. [PMID: 38622155 PMCID: PMC11018870 DOI: 10.1038/s41377-024-01439-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 02/26/2024] [Accepted: 03/25/2024] [Indexed: 04/17/2024]
Abstract
The examination of entanglement across various degrees of freedom has been pivotal in augmenting our understanding of fundamental physics, extending to high dimensional quantum states, and promising the scalability of quantum technologies. In this paper, we demonstrate the photon number path entanglement in the frequency domain by implementing a frequency beam splitter that converts the single-photon frequency to another with 50% probability using Bragg scattering four-wave mixing. The two-photon NOON state in a single-mode fiber is generated in the frequency domain, manifesting the two-photon interference with two-fold enhanced resolution compared to that of single-photon interference, showing the outstanding stability of the interferometer. This successful translation of quantum states in the frequency domain will pave the way toward the discovery of fascinating quantum phenomena and scalable quantum information processing.
Collapse
Affiliation(s)
- Dongjin Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Woncheol Shin
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Sebae Park
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Junyeop Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Heedeuk Shin
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea.
| |
Collapse
|
4
|
Kim DH, Hong S, Kim YS, Kim Y, Lee SW, Pooser RC, Oh K, Lee SY, Lee C, Lim HT. Distributed quantum sensing of multiple phases with fewer photons. Nat Commun 2024; 15:266. [PMID: 38212341 PMCID: PMC10784500 DOI: 10.1038/s41467-023-44204-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/04/2023] [Indexed: 01/13/2024] Open
Abstract
Distributed quantum metrology has drawn intense interest as it outperforms the optimal classical counterparts in estimating multiple distributed parameters. However, most schemes so far have required entangled resources consisting of photon numbers equal to or more than the parameter numbers, which is a fairly demanding requirement as the number of nodes increases. Here, we present a distributed quantum sensing scenario in which quantum-enhanced sensitivity can be achieved with fewer photons than the number of parameters. As an experimental demonstration, using a two-photon entangled state, we estimate four phases distributed 3 km away from the central node, resulting in a 2.2 dB sensitivity enhancement from the standard quantum limit. Our results show that the Heisenberg scaling can be achieved even when using fewer photons than the number of parameters. We believe our scheme will open a pathway to perform large-scale distributed quantum sensing with currently available entangled sources.
Collapse
Affiliation(s)
- Dong-Hyun Kim
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Seongjin Hong
- Department of Physics, Chung-Ang University, Seoul, 06974, Korea
| | - Yong-Su Kim
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
- Division of Nanoscience and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Korea
| | - Yosep Kim
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
- Department of Physics, Korea University, Seoul, 02841, Korea
| | - Seung-Woo Lee
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea
| | | | - Kyunghwan Oh
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Su-Yong Lee
- Emerging Science and Technology Directorate, Agency for Defense Development, Daejeon, 34186, Korea
- Weapon Systems Engineering, ADD School, University of Science and Technology, Daejeon, 34060, Korea
| | - Changhyoup Lee
- Korea Research Institute of Standards and Science, Daejeon, 34113, Korea
| | - Hyang-Tag Lim
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 02792, Korea.
- Division of Nanoscience and Technology, KIST School, Korea University of Science and Technology, Seoul, 02792, Korea.
| |
Collapse
|
5
|
Park G, Matsumoto I, Kiyohara T, Hofmann HF, Okamoto R, Takeuchi S. Realization of photon correlations beyond the linear optics limit. SCIENCE ADVANCES 2023; 9:eadj8146. [PMID: 38134279 PMCID: PMC10745675 DOI: 10.1126/sciadv.adj8146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/20/2023] [Indexed: 12/24/2023]
Abstract
Linear optical transformations of multiple single-photon inputs are fundamental for the development of photonic quantum technologies. Various nonclassical correlations can already be observed directly in states generated using only single-photon inputs and linear optics transformations. However, some quantum correlations require additional operations, and states that exhibit such correlations are classified as non-Fock states. Here, we demonstrate the generation of a two-photon three-mode non-Fock state that exhibits conditional quantum coherences that can only be achieved by non-Fock states. We determine the fidelity of the non-Fock state based on experimentally observed conditional visibilities that characterize the state and compare the result to the fidelity bounds for different classes of Fock and non-Fock states. Our experimental verification of the non-Fock character of the state provides insights into the technological requirements needed to achieve nonclassical correlations in multiphoton quantum optics.
Collapse
Affiliation(s)
- Geobae Park
- Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Issei Matsumoto
- Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Takayuki Kiyohara
- Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Holger F. Hofmann
- Graduate School of Advanced Science and Engineering, Hiroshima University, Kagamiyama 1-3-1, Higashi Hiroshima 739-8530, Japan
| | - Ryo Okamoto
- Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Shigeki Takeuchi
- Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| |
Collapse
|
6
|
Zhang M, Huang L, Liu Y, Zhao W, Wang W. Influence of multiphoton events on the quantum enhanced phase estimation. OPTICS EXPRESS 2022; 30:37833-37845. [PMID: 36258364 DOI: 10.1364/oe.468727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Quantum metrology can approach measurement precision of Heisenberg Limit using an ideal quantum source, which has attracted a great interest in fundamental physical studies. However, the quantum metrology precision is impressionable to the system noise in experiments. In this paper, we analyze the influence of multiphoton events on the phase estimation precision when using a nondeterministic single photon source. Our results show there are an extra bias and quantum enhanced region restriction due to multiphoton events, which declines the quantum phase estimation precision. A limitation of multiphoton probability is obtained for quantum enhanced phase estimation accuracy under different experimental model. Our results provide beneficial suggestions for improving quantum metrology precision in future experiments.
Collapse
|
7
|
Lee D, Pramanik T, Hong S, Cho YW, Lim HT, Chin S, Kim YS. Entangling three identical particles via spatial overlap. OPTICS EXPRESS 2022; 30:30525-30535. [PMID: 36242154 DOI: 10.1364/oe.460866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/22/2022] [Indexed: 06/16/2023]
Abstract
Quantum correlations between identical particles are at the heart of quantum technologies. Several studies with two identical particles have shown that the spatial overlap and indistinguishability between the particles are necessary for generating bipartite entanglement. On the other hand, researches on the extension to more than two-particle systems are limited by the practical difficulty to control multiple identical particles in laboratories. In this work, we propose schemes to generate two fundamental classes of genuine tripartite entanglement, i.e., GHZ and W classes, which are experimentally demonstrated using linear optics with three identical photons. We also show that the tripartite entanglement class decays from the genuine entanglement to the full separability as the particles become more distinguishable from each other. Our results support the prediction that particle indistinguishability is a fundamental element for entangling identical particles.
Collapse
|