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Cao C, Zhang L, Han YH, Yin PP, Fan L, Duan YW, Zhang R. Complete and faithful hyperentangled-Bell-state analysis of photon systems using a failure-heralded and fidelity-robust quantum gate. OPTICS EXPRESS 2020; 28:2857-2872. [PMID: 32121965 DOI: 10.1364/oe.384360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 01/11/2020] [Indexed: 06/10/2023]
Abstract
Hyperentangled-Bell-state analysis (HBSA) represents a key step in many quantum information processing schemes that utilize hyperentangled states. In this paper, we present a complete and faithful HBSA scheme for two-photon quantum systems hyperentangled in both the polarization and spatial-mode degrees of freedom, using a failure-heralded and fidelity-robust quantum swap gate for the polarization states of two photons (P-SWAP gate), constructed with a singly charged semiconductor quantum dot (QD) in a double-sided optical microcavity (double-sided QD-cavity system) and some linear-optical elements. Compared with the previously proposed complete HBSA schemes using different auxiliary tools such as parity-check quantum nondemonlition detectors or additional entangled states, our scheme significantly simplifies the analysis process and saves the quantum resource. Unlike the previous schemes based on the ideal optical giant circular birefringence induced by a single-electron spin in a double-sided QD-cavity system, our scheme guarantees the robust fidelity and relaxes the requirement on the QD-cavity parameters. These features indicate that our scheme may be more feasible and useful in practical applications based on the photonic hyperentanglement.
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2
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Gong M, Chen MC, Zheng Y, Wang S, Zha C, Deng H, Yan Z, Rong H, Wu Y, Li S, Chen F, Zhao Y, Liang F, Lin J, Xu Y, Guo C, Sun L, Castellano AD, Wang H, Peng C, Lu CY, Zhu X, Pan JW. Genuine 12-Qubit Entanglement on a Superconducting Quantum Processor. PHYSICAL REVIEW LETTERS 2019; 122:110501. [PMID: 30951346 DOI: 10.1103/physrevlett.122.110501] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Indexed: 06/09/2023]
Abstract
We report the preparation and verification of a genuine 12-qubit entanglement in a superconducting processor. The processor that we designed and fabricated has qubits lying on a 1D chain with relaxation times ranging from 29.6 to 54.6 μs. The fidelity of the 12-qubit entanglement was measured to be above 0.5544±0.0025, exceeding the genuine multipartite entanglement threshold by 21 statistical standard deviations. After thermal cycling, the 12-qubit state fidelity was further improved to be above 0.707±0.008. Our entangling circuit to generate linear cluster states is depth invariant in the number of qubits and uses single- and double-qubit gates instead of collective interactions. Our results are a substantial step towards large-scale random circuit sampling and scalable measurement-based quantum computing.
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Affiliation(s)
- Ming Gong
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Ming-Cheng Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Yarui Zheng
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Shiyu Wang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Chen Zha
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Hui Deng
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Zhiguang Yan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Hao Rong
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Yulin Wu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Shaowei Li
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Fusheng Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Youwei Zhao
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Futian Liang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Jin Lin
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Yu Xu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Cheng Guo
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Lihua Sun
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Anthony D Castellano
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Haohua Wang
- Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Chengzhi Peng
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Chao-Yang Lu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Xiaobo Zhu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, 10 University of Science and Technology of China, Shanghai 201315, China
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3
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Deng FG, Ren BC, Li XH. Quantum hyperentanglement and its applications in quantum information processing. Sci Bull (Beijing) 2017; 62:46-68. [PMID: 36718070 DOI: 10.1016/j.scib.2016.11.007] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/14/2016] [Accepted: 11/14/2016] [Indexed: 02/01/2023]
Abstract
Hyperentanglement is a promising resource in quantum information processing with its high capacity character, defined as the entanglement in multiple degrees of freedom (DOFs) of a quantum system, such as polarization, spatial-mode, orbit-angular-momentum, time-bin and frequency DOFs of photons. Recently, hyperentanglement attracts much attention as all the multiple DOFs can be used to carry information in quantum information processing fully. In this review, we present an overview of the progress achieved so far in the field of hyperentanglement in photon systems and some of its important applications in quantum information processing, including hyperentanglement generation, complete hyperentangled-Bell-state analysis, hyperentanglement concentration, and hyperentanglement purification for high-capacity long-distance quantum communication. Also, a scheme for hyper-controlled-not gate is introduced for hyperparallel photonic quantum computation, which can perform two controlled-not gate operations on both the polarization and spatial-mode DOFs and depress the resources consumed and the photonic dissipation.
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Affiliation(s)
- Fu-Guo Deng
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China.
| | - Bao-Cang Ren
- Department of Physics, Capital Normal University, Beijing 100048, China.
| | - Xi-Han Li
- Department of Physics, Chongqing University, Chongqing 400044, China; Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada.
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4
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Ciampini MA, Orieux A, Paesani S, Sciarrino F, Corrielli G, Crespi A, Ramponi R, Osellame R, Mataloni P. Path-polarization hyperentangled and cluster states of photons on a chip. LIGHT, SCIENCE & APPLICATIONS 2016; 5:e16064. [PMID: 30167159 PMCID: PMC6059950 DOI: 10.1038/lsa.2016.64] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 12/13/2015] [Accepted: 01/05/2016] [Indexed: 05/13/2023]
Abstract
Encoding many qubits in different degrees of freedom (DOFs) of single photons is one of the routes toward enlarging the Hilbert space spanned by a photonic quantum state. Hyperentangled photon states (that is, states showing entanglement in multiple DOFs) have demonstrated significant implications for both fundamental physics tests and quantum communication and computation. Increasing the number of qubits of photonic experiments requires miniaturization and integration of the basic elements, and functions to guarantee the setup stability, which motivates the development of technologies allowing the precise control of different photonic DOFs on a chip. We demonstrate the contextual use of path and polarization qubits propagating within an integrated quantum circuit. We tested the properties of four-qubit linear cluster states built on both DOFs, and we exploited them to perform the Grover's search algorithm according to the one-way quantum computation model. Our results pave the way toward the full integration on a chip of hybrid multi-qubit multiphoton states.
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Affiliation(s)
| | - Adeline Orieux
- Dipartimento di Fisica—Sapienza Università di Roma, I-00185 Roma, Italy
| | - Stefano Paesani
- Dipartimento di Fisica—Sapienza Università di Roma, I-00185 Roma, Italy
| | - Fabio Sciarrino
- Dipartimento di Fisica—Sapienza Università di Roma, I-00185 Roma, Italy
| | - Giacomo Corrielli
- Istituto di Fotonica e Nanotecnologie—Consiglio Nazionale delle Ricerche (IFN-CNR), I-20133 Milano, Italy
- Dipartimento di Fisica—Politecnico di Milano, I-20133 Milano, Italy
| | - Andrea Crespi
- Istituto di Fotonica e Nanotecnologie—Consiglio Nazionale delle Ricerche (IFN-CNR), I-20133 Milano, Italy
- Dipartimento di Fisica—Politecnico di Milano, I-20133 Milano, Italy
| | - Roberta Ramponi
- Istituto di Fotonica e Nanotecnologie—Consiglio Nazionale delle Ricerche (IFN-CNR), I-20133 Milano, Italy
- Dipartimento di Fisica—Politecnico di Milano, I-20133 Milano, Italy
| | - Roberto Osellame
- Istituto di Fotonica e Nanotecnologie—Consiglio Nazionale delle Ricerche (IFN-CNR), I-20133 Milano, Italy
- Dipartimento di Fisica—Politecnico di Milano, I-20133 Milano, Italy
| | - Paolo Mataloni
- Dipartimento di Fisica—Sapienza Università di Roma, I-00185 Roma, Italy
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5
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Luo MX, Deng Y, Li HR, Ma SY. Photonic ququart logic assisted by the cavity-QED system. Sci Rep 2015; 5:13255. [PMID: 26272869 PMCID: PMC4536487 DOI: 10.1038/srep13255] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 07/23/2015] [Indexed: 11/23/2022] Open
Abstract
Universal quantum logic gates are important elements for a quantum computer. In contrast to previous constructions of qubit systems, we investigate the possibility of ququart systems (four-dimensional states) dependent on two DOFs of photon systems. We propose some useful one-parameter four-dimensional quantum transformations for the construction of universal ququart logic gates. The interface between the spin of a photon and an electron spin confined in a quantum dot embedded in a microcavity is applied to build universal ququart logic gates on the photon system with two freedoms. Our elementary controlled-ququart gates cost no more than 8 CNOT gates in a qubit system, which is far less than the 104 CNOT gates required for a general four-qubit logic gate. The ququart logic is also used to generate useful hyperentanglements and hyperentanglement-assisted quantum error-correcting code, which may be available in modern physical technology.
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Affiliation(s)
- Ming-Xing Luo
- Information Security and National Computing Grid Laboratory, Southwest Jiaotong University, Chengdu 610031, China
| | - Yun Deng
- School of Computer Science, Sichuan University of Science & Engineering, Zigong 64300, China
| | - Hui-Ran Li
- Information Security and National Computing Grid Laboratory, Southwest Jiaotong University, Chengdu 610031, China
| | - Song-Ya Ma
- School of Mathematics and Statistics, Henan University, Kaifeng 475004, China
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6
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Li CM, Chen K, Chen YN, Zhang Q, Chen YA, Pan JW. Genuine High-Order Einstein-Podolsky-Rosen Steering. PHYSICAL REVIEW LETTERS 2015; 115:010402. [PMID: 26182083 DOI: 10.1103/physrevlett.115.010402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Indexed: 06/04/2023]
Abstract
Einstein-Podolsky-Rosen (EPR) steering demonstrates that two parties share entanglement even if the measurement devices of one party are untrusted. Here, going beyond this bipartite concept, we develop a novel formalism to explore a large class of EPR steering from generic multipartite quantum systems of arbitrarily high dimensionality and degrees of freedom, such as graph states and hyperentangled systems. All of these quantum characteristics of genuine high-order EPR steering can be efficiently certified with few measurement settings in experiments. We faithfully demonstrate for the first time such generality by experimentally showing genuine four-partite EPR steering and applications to universal one-way quantum computing. Our formalism provides a new insight into the intermediate type of genuine multipartite Bell nonlocality and potential applications to quantum information tasks and experiments in the presence of untrusted measurement devices.
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Affiliation(s)
- Che-Ming Li
- Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan
| | - Kai Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Yueh-Nan Chen
- Department of Physics and National Center for Theoretical Sciences, National Cheng-Kung University, Tainan 701, Taiwan
| | - Qiang Zhang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Yu-Ao Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
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Aolita L, de Melo F, Davidovich L. Open-system dynamics of entanglement: a key issues review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:042001. [PMID: 25811809 DOI: 10.1088/0034-4885/78/4/042001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
One of the greatest challenges in the fields of quantum information processing and quantum technologies is the detailed coherent control over each and every constituent of quantum systems with an ever increasing number of particles. Within this endeavor, harnessing of many-body entanglement against the detrimental effects of the environment is a major pressing issue. Besides being an important concept from a fundamental standpoint, entanglement has been recognized as a crucial resource for quantum speed-ups or performance enhancements over classical methods. Understanding and controlling many-body entanglement in open systems may have strong implications in quantum computing, quantum simulations of many-body systems, secure quantum communication or cryptography, quantum metrology, our understanding of the quantum-to-classical transition, and other important questions of quantum foundations.In this paper we present an overview of recent theoretical and experimental efforts to underpin the dynamics of entanglement under the influence of noise. Entanglement is thus taken as a dynamic quantity on its own, and we survey how it evolves due to the unavoidable interaction of the entangled system with its surroundings. We analyze several scenarios, corresponding to different families of states and environments, which render a very rich diversity of dynamical behaviors.In contrast to single-particle quantities, like populations and coherences, which typically vanish only asymptotically in time, entanglement may disappear at a finite time. In addition, important classes of entanglement display an exponential decay with the number of particles when subject to local noise, which poses yet another threat to the already-challenging scaling of quantum technologies. Other classes, however, turn out to be extremely robust against local noise. Theoretical results and recent experiments regarding the difference between local and global decoherence are summarized. Control and robustness-enhancement techniques, scaling laws, statistical and geometrical aspects of multipartite-entanglement decay are also reviewed; all in order to give a broad picture of entanglement dynamics in open quantum systems addressed to both theorists and experimentalists inside and outside the field of quantum information.
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Affiliation(s)
- Leandro Aolita
- Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany
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8
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Bell BA, Herrera-Martí DA, Tame MS, Markham D, Wadsworth WJ, Rarity JG. Experimental demonstration of a graph state quantum error-correction code. Nat Commun 2014; 5:3658. [DOI: 10.1038/ncomms4658] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 03/14/2014] [Indexed: 11/09/2022] Open
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9
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Lu HX, Cao LZ, Zhao JQ, Li YD, Wang XQ. Extreme violation of local realism with a hyper-entangled four-photon-eight-qubit Greenberger-Horne-Zelinger state. Sci Rep 2014; 4:4476. [PMID: 24667345 PMCID: PMC3966034 DOI: 10.1038/srep04476] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/11/2014] [Indexed: 11/15/2022] Open
Abstract
The highest qubit Ardehali inequality violation with 203 standard deviations is first experimentally demonstrated using the hyper-entangled four-photon-eight-qubit Greenberger-Horne-Zeilinger (GHZ) state. Moreover, we experimentally investigate the robustness of the Ardehali inequality for the four-, six-, and eight-qubit GHZ states in a rotary noisy environment systematically. Our results first validate the Ardehali' theoretical statement of relation between violation of Ardehali inequality and particle number, and proved that Ardehali inequality is more robust against noise in larger number qubit GHZ states, and provided an experimental benchmark for us to estimate the safety of quantum channel in the noisy environment.
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Affiliation(s)
- Huai-Xin Lu
- Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061, China
| | - Lian-Zhen Cao
- Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061, China
| | - Jia-Qiang Zhao
- Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061, China
| | - Ying-De Li
- Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061, China
| | - Xiao-Qin Wang
- Department of Physics and Electronic Science, Weifang University, Weifang, Shandong 261061, China
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10
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Chiuri A, Greganti C, Paternostro M, Vallone G, Mataloni P. Experimental quantum networking protocols via four-qubit hyperentangled Dicke states. PHYSICAL REVIEW LETTERS 2012; 109:173604. [PMID: 23215188 DOI: 10.1103/physrevlett.109.173604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Indexed: 06/01/2023]
Abstract
We report the experimental demonstration of two quantum networking protocols, namely quantum 1→3 telecloning and open-destination teleportation, implemented using a four-qubit register whose state is encoded in a high-quality two-photon hyperentangled Dicke state. The state resource is characterized using criteria based on multipartite entanglement witnesses. We explore the characteristic entanglement-sharing structure of a Dicke state by implementing high-fidelity projections of the four-qubit resource onto lower-dimensional states. Our work demonstrates for the first time the usefulness of Dicke states for quantum information processing.
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Affiliation(s)
- A Chiuri
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
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11
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Ukai R, Iwata N, Shimokawa Y, Armstrong SC, Politi A, Yoshikawa JI, van Loock P, Furusawa A. Demonstration of unconditional one-way quantum computations for continuous variables. PHYSICAL REVIEW LETTERS 2011; 106:240504. [PMID: 21770557 DOI: 10.1103/physrevlett.106.240504] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Indexed: 05/31/2023]
Abstract
One-way quantum computation is a very promising candidate to fulfill the capabilities of quantum information processing. Here we demonstrate an important set of unitary operations for continuous variables using a linear cluster state of four entangled optical modes. These operations are performed in a fully measurement-controlled and completely unconditional fashion. We implement three different levels of squeezing operations and a Fourier transformation, all of which are accessible by selecting the correct quadrature measurement angles of the homodyne detections. Though not sufficient, these linear transformations are necessary for universal quantum computation.
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Affiliation(s)
- Ryuji Ukai
- Department of Applied Physics, School of Engineering, The University of Tokyo, Tokyo, Japan
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12
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Teleportation-based realization of an optical quantum two-qubit entangling gate. Proc Natl Acad Sci U S A 2010; 107:20869-74. [PMID: 21098305 DOI: 10.1073/pnas.1005720107] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In recent years, there has been heightened interest in quantum teleportation, which allows for the transfer of unknown quantum states over arbitrary distances. Quantum teleportation not only serves as an essential ingredient in long-distance quantum communication, but also provides enabling technologies for practical quantum computation. Of particular interest is the scheme proposed by D. Gottesman and I. L. Chuang [(1999) Nature 402:390-393], showing that quantum gates can be implemented by teleporting qubits with the help of some special entangled states. Therefore, the construction of a quantum computer can be simply based on some multiparticle entangled states, Bell-state measurements, and single-qubit operations. The feasibility of this scheme relaxes experimental constraints on realizing universal quantum computation. Using two different methods, we demonstrate the smallest nontrivial module in such a scheme--a teleportation-based quantum entangling gate for two different photonic qubits. One uses a high-fidelity six-photon interferometer to realize controlled-NOT gates, and the other uses four-photon hyperentanglement to realize controlled-Phase gates. The results clearly demonstrate the working principles and the entangling capability of the gates. Our experiment represents an important step toward the realization of practical quantum computers and could lead to many further applications in linear optics quantum information processing.
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13
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Gao WB, Xu P, Yao XC, Gühne O, Cabello A, Lu CY, Peng CZ, Chen ZB, Pan JW. Experimental realization of a controlled-NOT gate with four-photon six-qubit cluster states. PHYSICAL REVIEW LETTERS 2010; 104:020501. [PMID: 20366576 DOI: 10.1103/physrevlett.104.020501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Indexed: 05/29/2023]
Abstract
We experimentally demonstrate an optical controlled-NOT (CNOT) gate with arbitrary single inputs based on a 4-photon 6-qubit cluster state entangled both in polarization and spatial modes. We first generate the 6-qubit state, and then, by performing single-qubit measurements, the CNOT gate is applied to arbitrary single input qubits. To characterize the performance of the gate, we estimate its quantum process fidelity and prove its entangling capability. In addition, our results show that the gate cannot be reproduced by local operations and classical communication. Our experiment shows that such hyper-entangled cluster states are promising candidates for efficient optical quantum computation.
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Affiliation(s)
- Wei-Bo Gao
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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Ceccarelli R, Vallone G, De Martini F, Mataloni P, Cabello A. Experimental entanglement and nonlocality of a two-photon six-qubit cluster state. PHYSICAL REVIEW LETTERS 2009; 103:160401. [PMID: 19905673 DOI: 10.1103/physrevlett.103.160401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Indexed: 05/28/2023]
Abstract
We create a six-qubit linear cluster state by transforming a two-photon hyperentangled state in which three qubits are encoded in each particle, one in the polarization and two in the linear momentum degrees of freedom. For this state, we demonstrate genuine six-qubit entanglement, persistency of entanglement against the loss of qubits, and higher violation than in previous experiments on Bell inequalities of the Mermin type.
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Affiliation(s)
- Raino Ceccarelli
- Dipartimento di Fisica della Sapienza Università di Roma, Roma 00185, Italy
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15
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Cavalcanti D, Chaves R, Aolita L, Davidovich L, Acín A. Open-system dynamics of graph-state entanglement. PHYSICAL REVIEW LETTERS 2009; 103:030502. [PMID: 19659258 DOI: 10.1103/physrevlett.103.030502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Indexed: 05/28/2023]
Abstract
We consider graph states of an arbitrary number of particles undergoing generic decoherence. We present methods to obtain lower and upper bounds for the system's entanglement in terms of that of considerably smaller subsystems. For an important class of noisy channels, namely, the Pauli maps, these bounds coincide and thus provide the exact analytical expression for the entanglement evolution. All of the results apply also to (mixed) graph-diagonal states and hold true for any convex entanglement monotone. Since any state can be locally depolarized to some graph-diagonal state, our method provides a lower bound for the entanglement decay of any arbitrary state. Finally, this formalism also allows for the direct identification of the robustness under size scaling of graph states in the presence of decoherence, merely by inspection of their connectivities.
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Affiliation(s)
- Daniel Cavalcanti
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain
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16
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Rossi A, Vallone G, Chiuri A, De Martini F, Mataloni P. Multipath entanglement of two photons. PHYSICAL REVIEW LETTERS 2009; 102:153902. [PMID: 19518632 DOI: 10.1103/physrevlett.102.153902] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Indexed: 05/27/2023]
Abstract
We present a novel optical device based on an integrated system of microlenses and single-mode optical fibers. It allows us to collect and direct into many modes two photons generated by spontaneous parametric down-conversion. By this device multiqubit entangled states and/or multilevel qudit states of two photons, encoded in the longitudinal momentum degree of freedom, are created. The multipath photon entanglement realized by this device is expected to find important applications in modern quantum information technology.
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Affiliation(s)
- Alessandro Rossi
- Dipartimento di Fisica, Sapienza Università di Roma, Roma 00185, Italy
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17
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Spagnolo N, Vitelli C, Giacomini S, Sciarrino F, De Martini F. Polarization preserving ultra fast optical shutter for quantum information processing. OPTICS EXPRESS 2008; 16:17609-17615. [PMID: 18958041 DOI: 10.1364/oe.16.017609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present the realization of a ultra fast shutter for optical fields, which allows to preserve a generic polarization state, based on a self-stabilized interferometer. It exhibits high (or low) transmittivity when turned on (or inactive), while the fidelity of the polarization state is high. The shutter is realized through two beam displacing prisms and a longitudinal Pockels cell. This can represent a useful tool for controlling light-atom interfaces in quantum information processing.
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Affiliation(s)
- Nicoló Spagnolo
- Dipartimento di Fisica dell'Universitá La Sapienza and Consorzio Nazionale, Interuniversitario per le Scienze Fisiche della Materia, Roma 00185, Italy
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