1
|
Bayerbach MJ, D'Aurelio SE, van Loock P, Barz S. Bell-state measurement exceeding 50% success probability with linear optics. SCIENCE ADVANCES 2023; 9:eadf4080. [PMID: 37556537 DOI: 10.1126/sciadv.adf4080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 07/06/2023] [Indexed: 08/11/2023]
Abstract
Bell-state projections serve as a fundamental basis for most quantum communication and computing protocols today. However, with current Bell-state measurement schemes based on linear optics, only two of four Bell states can be identified, which means that the maximum success probability of this vital step cannot exceed 50%. Here, we experimentally demonstrate a scheme that amends the original measurement with additional modes in the form of ancillary photons, which leads to a more complex measurement pattern, and ultimately a higher success probability of 62.5%. Experimentally, we achieve a success probability of (57.9 ± 1.4)%, a substantial improvement over the conventional scheme. With the possibility of extending the protocol to a larger number of ancillary photons, our work paves the way toward more efficient realizations of quantum technologies based on Bell-state measurements.
Collapse
Affiliation(s)
- Matthias J Bayerbach
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology (IQST), University of Stuttgart, 70569 Stuttgart, Germany
| | - Simone E D'Aurelio
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology (IQST), University of Stuttgart, 70569 Stuttgart, Germany
| | - Peter van Loock
- Johannes-Gutenberg University of Mainz, Institute of Physics, Staudingerweg 7, 55128 Mainz, Germany
| | - Stefanie Barz
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology (IQST), University of Stuttgart, 70569 Stuttgart, Germany
| |
Collapse
|
2
|
Piveteau A, Pauwels J, Håkansson E, Muhammad S, Bourennane M, Tavakoli A. Entanglement-assisted quantum communication with simple measurements. Nat Commun 2022; 13:7878. [PMID: 36550100 PMCID: PMC9780301 DOI: 10.1038/s41467-022-33922-5] [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: 05/20/2022] [Accepted: 10/07/2022] [Indexed: 12/24/2022] Open
Abstract
Dense coding is the seminal example of how entanglement can boost qubit communication, from sending one bit to sending two bits. This is made possible by projecting separate particles onto a maximally entangled basis. We investigate more general communication tasks, in both theory and experiment, and show that simpler measurements enable strong and sometimes even optimal entanglement-assisted qubit communication protocols. Using only partial Bell state analysers for two qubits, we demonstrate quantum correlations that cannot be simulated with two bits of classical communication. Then, we show that there exists an established and operationally meaningful task for which product measurements are sufficient for the strongest possible quantum predictions based on a maximally entangled two-qubit state. Our results reveal that there are scenarios in which the power of entanglement in enhancing quantum communication can be harvested in simple and scalable optical experiments.
Collapse
Affiliation(s)
- Amélie Piveteau
- grid.10548.380000 0004 1936 9377Department of Physics, Stockholm University, S-10691 Stockholm, Sweden
| | - Jef Pauwels
- grid.4989.c0000 0001 2348 0746Laboratoire d’Information Quantique, CP 225, Université libre de Bruxelles (ULB), Av. F. D. Roosevelt 50, 1050 Bruxelles, Belgium
| | - Emil Håkansson
- grid.10548.380000 0004 1936 9377Department of Physics, Stockholm University, S-10691 Stockholm, Sweden ,Hitachi Energy Research, Forskargränd 7, 72219 Västerås, Sweden
| | - Sadiq Muhammad
- grid.10548.380000 0004 1936 9377Department of Physics, Stockholm University, S-10691 Stockholm, Sweden
| | - Mohamed Bourennane
- grid.10548.380000 0004 1936 9377Department of Physics, Stockholm University, S-10691 Stockholm, Sweden
| | - Armin Tavakoli
- grid.4299.60000 0001 2169 3852Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria ,grid.5329.d0000 0001 2348 4034Atominstitut, Technische Universität Wien, Stadionallee 2, 1020 Vienna, Austria
| |
Collapse
|
3
|
Wang C, Chen Y, Chen L. Four-dimensional orbital angular momentum Bell-state measurement assisted by the auxiliary polarization and path degrees of freedom. OPTICS EXPRESS 2022; 30:34468-34478. [PMID: 36242458 DOI: 10.1364/oe.469704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
The orbital angular momentum (OAM) carried by twisted photons provides a promising playground for high-dimensional quantum information processing. While Bell-state measurement is the cornerstone for various quantum information applications, the deterministic discrimination of the complete high-dimensional Bell states with linear optics remains relatively unexplored in the OAM state space. Here, we demonstrate a theoretical scheme for the complete four-dimensional OAM Bell-state measurement by using the single-photon hyperentangled state analyzer, in which the auxiliary two-dimensional polarization entanglement and two-dimensional path entanglement are utilized. Our scheme offers an alternative route toward enhancing the channel capacity in quantum communication and increasing the robustness against deleterious noise in practical experiments with twisted photons.
Collapse
|
4
|
Li ZD, Mao YL, Weilenmann M, Tavakoli A, Chen H, Feng L, Yang SJ, Renou MO, Trillo D, Le TP, Gisin N, Acín A, Navascués M, Wang Z, Fan J. Testing Real Quantum Theory in an Optical Quantum Network. PHYSICAL REVIEW LETTERS 2022; 128:040402. [PMID: 35148126 DOI: 10.1103/physrevlett.128.040402] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Quantum theory is commonly formulated in complex Hilbert spaces. However, the question of whether complex numbers need to be given a fundamental role in the theory has been debated since its pioneering days. Recently it has been shown that tests in the spirit of a Bell inequality can reveal quantum predictions in entanglement swapping scenarios that cannot be modeled by the natural real-number analog of standard quantum theory. Here, we tailor such tests for implementation in state-of-the-art photonic systems. We experimentally demonstrate quantum correlations in a network of three parties and two independent EPR sources that violate the constraints of real quantum theory by over 4.5 standard deviations, hence disproving real quantum theory as a universal physical theory.
Collapse
Affiliation(s)
- Zheng-Da Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ya-Li Mao
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Mirjam Weilenmann
- Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria
| | - Armin Tavakoli
- Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria
- Institute for Atomic and Subatomic Physics, Vienna University of Technology, 1020 Vienna, Austria
| | - Hu Chen
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lixin Feng
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sheng-Jun Yang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Marc-Olivier Renou
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - David Trillo
- Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria
| | - Thinh P Le
- Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria
| | - Nicolas Gisin
- Group of Applied Physics, University of Geneva, 1211 Geneva 4, Switzerland
- Schaffhausen Institute of Technology - SIT, 1211 Geneva 4, Switzerland
| | - Antonio Acín
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA, Pg. Lluis Companys 23, 08010 Barcelona, Spain
| | - Miguel Navascués
- Institute for Quantum Optics and Quantum Information - IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria
| | - Zizhu Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Jingyun Fan
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| |
Collapse
|
5
|
Sheng YB, Zhou L, Long GL. One-step quantum secure direct communication. Sci Bull (Beijing) 2021; 67:367-374. [DOI: 10.1016/j.scib.2021.11.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/13/2021] [Accepted: 10/26/2021] [Indexed: 10/19/2022]
|
6
|
Kozubov AV, Gaidash AA, Kiselev AD, Miroshnichenko GP. Filtration mapping as complete Bell state analyzer for bosonic particles. Sci Rep 2021; 11:14236. [PMID: 34244596 PMCID: PMC8270949 DOI: 10.1038/s41598-021-93679-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/21/2021] [Indexed: 11/09/2022] Open
Abstract
In this paper, we present the approach to complete Bell state analysis based on filtering mapping. The key distinctive feature of this appoach is that it avoids complications related to using either hyperentanglement or representation of the Bell states as concatenated Greenber-Horne-Zeilinger (C-GHZ) state to perform discrimination procedure. We describe two techniques developed within the suggested approach and based on two-step algorithms with two different types of filtration mapping which can be called the non-demolition and semi-demolition filtrations. In the method involving non-demolition filtration measurement the filtration process employs cross-Kerr nonlinearity and the probe mode to distinguish between the two pairs of the Bell states. In the case of semi-demolition measurement, the two states are unambiguously discriminated and hence destroyed, whereas filtraton keeps the other two states intact. We show that the measurement that destroys the single photon subspace in every mode and preserves the superposition of zero and two photons can be realized with discrete photodetection based on microresonator with atoms.
Collapse
Affiliation(s)
- A V Kozubov
- Department of Mathematical Methods for Quantum Technologies, Steklov Mathematical Institute of Russian Academy of Sciences, 119991, Moscow, Russia.
- Laboratory of Quantum Processes and Measurements, ITMO University, Kadetskaya Line 3b, 199034, Saint Petersburg, Russia.
| | - A A Gaidash
- Department of Mathematical Methods for Quantum Technologies, Steklov Mathematical Institute of Russian Academy of Sciences, 119991, Moscow, Russia
- Laboratory of Quantum Processes and Measurements, ITMO University, Kadetskaya Line 3b, 199034, Saint Petersburg, Russia
| | - A D Kiselev
- Laboratory of Quantum Processes and Measurements, ITMO University, Kadetskaya Line 3b, 199034, Saint Petersburg, Russia
- Faculty of Physics, St. Petersburg State University, 199034, Saint Petersburg, Russia
| | - G P Miroshnichenko
- Faculty of Laser Photonics and Optoelectronics, ITMO University, 49 Kronverksky Pr., 197101, Saint Petersburg, Russia
| |
Collapse
|
7
|
Liu Q, Song GZ, Qiu TH, Zhang XM, Ma HY, Zhang M. Hyperentanglement concentration of nonlocal two-photon six-qubit systems via the cross-Kerr nonlinearity. Sci Rep 2020; 10:21444. [PMID: 33293577 PMCID: PMC7722746 DOI: 10.1038/s41598-020-78529-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/26/2020] [Indexed: 11/15/2022] Open
Abstract
We present an efficient hyperentanglement concentration protocol (hyper-ECP) for two-photon six-qubit systems in nonlocal partially hyperentangled Bell states with unknown parameters. In our scheme, we use two identical partially hyperentangled states which are simultaneously entangled in polarization and two different longitudinal momentum degrees of freedom (DOFs) to distill the maximally hyperentangled Bell state. The quantum nondemolition detectors based on the cross-Kerr nonlinearity are used to realize the parity checks of two-photon systems in three DOFs. The hyper-ECP can extract all the useful entanglement source, and the success probability can reach the theory limit with the help of iteration. All these advantages make our hyper-ECP useful in long-distance quantum communication in the future.
Collapse
Affiliation(s)
- Qian Liu
- Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China.
| | - Guo-Zhu Song
- College of Physics and Materials Science, Tianjin Normal University, Tianjin, 300387, China
| | - Tian-Hui Qiu
- Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China
| | - Xiao-Min Zhang
- Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China
| | - Hong-Yang Ma
- Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China
| | - Mei Zhang
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing, 100875, China
| |
Collapse
|
8
|
Identification of networking quantum teleportation on 14-qubit IBM universal quantum computer. Sci Rep 2020; 10:3093. [PMID: 32080312 PMCID: PMC7033242 DOI: 10.1038/s41598-020-60061-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/07/2020] [Indexed: 11/08/2022] Open
Abstract
Quantum teleportation enables networking participants to move an unknown quantum state between the nodes of a quantum network, and hence constitutes an essential element in constructing large-sale quantum processors with a quantum modular architecture. Herein, we propose two protocols for teleporting qubits through an N-node quantum network in a highly-entangled box-cluster state or chain-type cluster state. The proposed protocols are systematically scalable to an arbitrary finite number N and applicable to arbitrary size of modules. The protocol based on a box-cluster state is implemented on a 14-qubit IBM quantum computer for N up to 12. To identify faithful networking teleportation, namely that the elements on real devices required for the networking teleportation process are all qualified for achieving teleportation task, we quantify quantum-mechanical processes using a generic classical-process model through which any classical strategies of mimicry of teleportation can be ruled out. From the viewpoint of achieving a genuinely quantum-mechanical process, the present work provides a novel toolbox consisting of the networking teleportation protocols and the criteria for identifying faithful teleportation for universal quantum computers with modular architectures and facilitates further improvements in the reliability of quantum-information processing.
Collapse
|
9
|
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.
Collapse
|
10
|
Qiu TH, Li H, Xie M, Liu Q, Ma HY. Coherent generation and manipulation of entangled stationary photons based on a multiple degrees of freedom quantum memory. OPTICS EXPRESS 2019; 27:27477-27487. [PMID: 31684513 DOI: 10.1364/oe.27.027477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 08/28/2019] [Indexed: 06/10/2023]
Abstract
We propose a quantum memory, each subsystem of which is comprised of two double M-type systems of cold atoms, for the first generation of entangled stationary photons (ESPs). Through the active operation of two pairs of counter-propagating controlling fields in time, the reversible transfer of entanglement between photons and atomic ensembles is realized, and the ESPs can be created due to the tight coupling and balanced competition between the corresponding retrieved signal photons. The reduced density matrix in the photon-polarization basis, which provides the lower bound for any purported entanglement, is constructed for discussing the dynamics evolution of the entanglement in terms of the concurrence. We show that the present scheme can be employed for the entangled photons encoded in degrees of freedom (DOFs) of polarization and orbital angular momentum. Such a multiple DOFs dependent scheme, with many benefits over that in a single one, could pave the way toward quantum nonlinear optics without a cavity and could greatly enhance the tunability and capacity for the quantum information processing.
Collapse
|
11
|
Abstract
Quantum superdense coding enables a sender to encode a two-bit classical message in one qubit using the preshared entanglement. In this paper, we develop a superdense coding protocol using a dual quantum Zeno (DQZ) gate to take the full advantage of quantum superdense coding from the complete Bell-state analysis. We verify that the DQZ gate allows remote parties to achieve the distinguishability of orthonormal Bell states in a semi-counterfactual manner and the DQZ superdense coding achieves high throughput efficiency as a function of cycle numbers for the Bell-state analyzer.
Collapse
|
12
|
Liu JZ, Chen NY, Liu WQ, Wei HR, Hua M. Hyperparallel transistor, router and dynamic random access memory with unity fidelities. OPTICS EXPRESS 2019; 27:21380-21394. [PMID: 31510217 DOI: 10.1364/oe.27.021380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/23/2019] [Indexed: 06/10/2023]
Abstract
We theoretically implement some hyperparallel optical elements, including quantum single photon transistor, router, and dynamic random access memory (DRAM). The inevitable side leakage and the imperfect birefringence of the quantum dot (QD)-cavity mediates are taken into account, and unity fidelities of our optical elements can be achieved. The hyperparallel constructions are based on polarization and spatial degrees of freedom (DOFs) of the photon to increase the parallel efficiency, improve the capacity of channel, save the quantum resources, reduce the operation time, and decrease the environment noises. Moreover, the practical schemes are robust against the side leakage and the coupling strength limitation in the microcavities.
Collapse
|
13
|
Kong LJ, Liu R, Qi WR, Wang ZX, Huang SY, Wang Q, Tu C, Li Y, Wang HT. Manipulation of eight-dimensional Bell-like states. SCIENCE ADVANCES 2019; 5:eaat9206. [PMID: 31214646 PMCID: PMC6570514 DOI: 10.1126/sciadv.aat9206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/09/2019] [Indexed: 05/25/2023]
Abstract
High-dimensional Bell-like states are necessary for increasing the channel capacity of the quantum protocol. However, their preparation and measurement are still huge challenges, especially for the latter. Here, we prepare an initial eight-dimensional Bell-like state based on hyperentanglement of spin and orbital angular momentum (OAM) of the first and the third orders. We design simple unitary operations to produce eight Bell-like states, which can be distinguished completely in theory among each other. We propose and illustrate a multiple projective measurement scheme composed of only linear optical elements and experimentally demonstrate that all the eight hyperentangled Bell-like states can be completely distinguished by our scheme. Our idea of manipulating the eight Bell-like states is beneficial to achieve the 3-bit channel capacity of quantum protocol, opening the door for extending applications of OAM states in future quantum information technology.
Collapse
Affiliation(s)
- Ling-Jun Kong
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Liu
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Wen-Rong Qi
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Zhou-Xiang Wang
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Shuang-Yin Huang
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Qiang Wang
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Chenghou Tu
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Yongnan Li
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Hui-Tian Wang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| |
Collapse
|
14
|
Li CY, Shen Y. Asymmetrical hyperentanglement concentration for entanglement of polarization and orbital angular momentum. OPTICS EXPRESS 2019; 27:13172-13181. [PMID: 31052846 DOI: 10.1364/oe.27.013172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
We propose two hyperentanglement concentration protocols (hyper-ECPs) for two-photon entangled states in the polarization and orbital angular momentum degrees of freedom. The two cases distilling a maximally hyperentangled state from partially entangled pure state with unknown parameters and known parameters are dissected respectively. Both of the protocols require only linear optical elements which make our protocols more feasible for current technologies. In our protocols, the remote parties perform different local operations, which will reduce everyone's operation and improve the total efficiency. Each of them has the theoretical maximum success probability in the corresponding situation. The hyper-ECPs can be exploited simply to hyperentangled Greenberger-Horne-Zeilinger states.
Collapse
|
15
|
Sandoval OE, Lingaraju NB, Imany P, Leaird DE, Brodsky M, Weiner AM. Polarization diversity phase modulator for measuring frequency-bin entanglement of a biphoton frequency comb in a depolarized channel. OPTICS LETTERS 2019; 44:1674-1677. [PMID: 30933119 DOI: 10.1364/ol.44.001674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 02/27/2019] [Indexed: 06/09/2023]
Abstract
Phase modulation has emerged as a technique to create and manipulate high-dimensional frequency-bin entanglement. A necessary step to extending this technique to depolarized channels, such as those in a quantum networking environment, is the ability to perform phase modulation independent of photon polarization. This is also necessary to harness hyperentanglement in the polarization and frequency degrees of freedom for operations such as Bell state discrimination. However, practical phase modulators are generally sensitive to the polarization of light, and this makes them unsuited to such applications. We overcome this limitation by implementing a polarization diversity scheme to measure frequency-bin entanglement for arbitrary orientations of co- and cross-polarized time-energy entangled photon pairs.
Collapse
|
16
|
Wang GY, Ren BC, Deng FG, Long GL. Complete analysis of hyperentangled Bell states assisted with auxiliary hyperentanglement. OPTICS EXPRESS 2019; 27:8994-9003. [PMID: 31052709 DOI: 10.1364/oe.27.008994] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
We present a simple protocol for complete analysis of 16 hyperentangled Bell states of two-photon system in the polarization and the first longitudinal momentum degrees of freedom (DOFs). This complete analysis protocol is accomplished with the auxiliary hyperentangled Bell state in the frequency and the second longitudinal momentum DOFs utilizing the experimentally available optical elements including linear optical elements which manipulate the polarizations and the longitudinal momentums and the optical devices which manipulate frequencies of photons. This complete analysis protocol allows the transmission of log216=4 bits of classical information via quantum hyperdense coding scheme, which is the upper bound of the transmission capacity of the quantum hyperdense coding scheme based on 16 orthogonal hyperentangled Bell states. This complete analysis protocol has a potential to be experimentally realized and is useful for high-capacity quantum communication based on hyperentangled states.
Collapse
|
17
|
Flamini F, Spagnolo N, Sciarrino F. Photonic quantum information processing: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:016001. [PMID: 30421725 DOI: 10.1088/1361-6633/aad5b2] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Photonic quantum technologies represent a promising platform for several applications, ranging from long-distance communications to the simulation of complex phenomena. Indeed, the advantages offered by single photons do make them the candidate of choice for carrying quantum information in a broad variety of areas with a versatile approach. Furthermore, recent technological advances are now enabling first concrete applications of photonic quantum information processing. The goal of this manuscript is to provide the reader with a comprehensive review of the state of the art in this active field, with a due balance between theoretical, experimental and technological results. When more convenient, we will present significant achievements in tables or in schematic figures, in order to convey a global perspective of the several horizons that fall under the name of photonic quantum information.
Collapse
Affiliation(s)
- Fulvio Flamini
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | | | | |
Collapse
|
18
|
Wang M, Xu J, Yan F, Gao T. Entanglement concentration for polarization–spatial–time-bin hyperentangled Bell states. ACTA ACUST UNITED AC 2018. [DOI: 10.1209/0295-5075/123/60002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
19
|
Zaman F, Jeong Y, Shin H. Counterfactual Bell-State Analysis. Sci Rep 2018; 8:14641. [PMID: 30279547 PMCID: PMC6168595 DOI: 10.1038/s41598-018-32928-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/19/2018] [Indexed: 11/16/2022] Open
Abstract
The Bell-state analysis to distinguish between the four maximally entangled Bell states requires the joint measurement on entangled particles. However, spatially separated parties cannot perform the joint measurement. In this paper, we present a counterfactual Bell-state analysis based on the chained quantum Zeno effect. This counterfactual analysis not only enables us to perform a complete Bell-state analysis, but also enables spatially separated parties to distinguish between the four Bell states without transmitting any physical particle over the channel.
Collapse
Affiliation(s)
- Fakhar Zaman
- Department of Electronic Engineering, Kyung Hee University, Yongin-si, 17104, Korea
| | - Youngmin Jeong
- Department of Electronic Engineering, Kyung Hee University, Yongin-si, 17104, Korea.
| | - Hyundong Shin
- Department of Electronic Engineering, Kyung Hee University, Yongin-si, 17104, Korea.
| |
Collapse
|
20
|
Prilmüller M, Huber T, Müller M, Michler P, Weihs G, Predojević A. Hyperentanglement of Photons Emitted by a Quantum Dot. PHYSICAL REVIEW LETTERS 2018; 121:110503. [PMID: 30265086 DOI: 10.1103/physrevlett.121.110503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/04/2018] [Indexed: 05/28/2023]
Abstract
A hyperentangled state of light represents a valuable tool capable of reducing the experimental requirements and resource overheads, and it can improve the success rate of quantum information protocols. Here, we report on demonstration of polarization and time-bin hyperentangled photon pairs emitted from a single quantum dot. We achieved this result by applying resonant and coherent excitation on a quantum dot system with marginal fine structure splitting. Our results yield fidelities to the maximally entangled state of 0.81(6) and 0.87(4) in polarization and time bin, respectively.
Collapse
Affiliation(s)
- Maximilian Prilmüller
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Tobias Huber
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Markus Müller
- Institut für Halbleiteroptik und Funktionelle Grenzflächen and Center for Integrated Quantum Science and Technology (IQST) and SCoPE, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany
| | - Peter Michler
- Institut für Halbleiteroptik und Funktionelle Grenzflächen and Center for Integrated Quantum Science and Technology (IQST) and SCoPE, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany
| | - Gregor Weihs
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Ana Predojević
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
- Institute for Quantum Optics, Albert-Einstein-Allee 11, University of Ulm, 89081 Ulm, Germany
| |
Collapse
|
21
|
Hu XM, Guo Y, Liu BH, Huang YF, Li CF, Guo GC. Beating the channel capacity limit for superdense coding with entangled ququarts. SCIENCE ADVANCES 2018; 4:eaat9304. [PMID: 30035231 PMCID: PMC6054506 DOI: 10.1126/sciadv.aat9304] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/05/2018] [Indexed: 05/02/2023]
Abstract
Quantum superdense coding protocols enhance channel capacity by using shared quantum entanglement between two users. The channel capacity can be as high as 2 when one uses entangled qubits. However, this limit can be surpassed by using high-dimensional entanglement. We report an experiment that exceeds the limit using high-quality entangled ququarts with fidelities up to 0.98, demonstrating a channel capacity of 2.09 ± 0.01. The measured channel capacity is also higher than that obtained when transmitting only one ququart. We use the setup to transmit a five-color image with a fidelity of 0.952. Our experiment shows the great advantage of high-dimensional entanglement and will stimulate research on high-dimensional quantum information processes.
Collapse
Affiliation(s)
- Xiao-Min Hu
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Yu Guo
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Bi-Heng Liu
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Corresponding author. (B.-H.L.); (C.-F.L.)
| | - Yun-Feng Huang
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Chuan-Feng Li
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Corresponding author. (B.-H.L.); (C.-F.L.)
| | - Guang-Can Guo
- Chinese Academy of Sciences Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| |
Collapse
|
22
|
Hong CH, Heo J, Kang MS, Jang J, Yang HJ. Optical scheme for generating hyperentanglement having photonic qubit and time-bin via quantum dot and cross-Kerr nonlinearity. Sci Rep 2018; 8:2566. [PMID: 29416070 PMCID: PMC5803275 DOI: 10.1038/s41598-018-19970-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/10/2018] [Indexed: 11/16/2022] Open
Abstract
We design an optical scheme to generate hyperentanglement correlated with degrees of freedom (DOFs) via quantum dots (QDs), weak cross-Kerr nonlinearities (XKNLs), and linearly optical apparatuses (including time-bin encoders). For generating hyperentanglement having its own correlations for two DOFs (polarization and time-bin) on two photons, we employ the effects of optical nonlinearities using a QD (photon-electron), a parity gate (XKNLs), and time-bin encodings (linear optics). In our scheme, the first nonlinear multi-qubit gate utilizes the interactions between photons and an electron of QD confined in a single-sided cavity, and the parity gate (second gate) uses weak XKNLs, quantum bus, and photon-number-resolving measurement to entangle the polarizations of two photons. Finally, for efficiency in generating hyperentanglement and for the experimental implementation of this scheme, we discuss how the QD-cavity system can be performed reliably, and also discuss analysis of the immunity of the parity gate (XKNLs) against the decoherence effect.
Collapse
Affiliation(s)
- Chang Ho Hong
- Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Jino Heo
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
| | - Min Sung Kang
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Republic of Korea
| | - Jingak Jang
- Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Hyung Jin Yang
- Department of Physics, Korea University, Sejong, 339-700, Republic of Korea
| |
Collapse
|
23
|
Heo J, Kang MS, Hong CH, Yang HJ, Choi SG, Hong JP. Distribution of hybrid entanglement and hyperentanglement with time-bin for secure quantum channel under noise via weak cross-Kerr nonlinearity. Sci Rep 2017; 7:10208. [PMID: 28860529 PMCID: PMC5579062 DOI: 10.1038/s41598-017-09510-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/25/2017] [Indexed: 11/12/2022] Open
Abstract
We design schemes to generate and distribute hybrid entanglement and hyperentanglement correlated with degrees of freedom (polarization and time-bin) via weak cross-Kerr nonlinearities (XKNLs) and linear optical devices (including time-bin encoders). In our scheme, the multi-photon gates (which consist of XKNLs, quantum bus [qubus] beams, and photon-number-resolving [PNR] measurement) with time-bin encoders can generate hyperentanglement or hybrid entanglement. And we can also purify the entangled state (polarization) of two photons using only linear optical devices and time-bin encoders under a noisy (bit-flip) channel. Subsequently, through local operations (using a multi-photon gate via XKNLs) and classical communications, it is possible to generate a four-qubit hybrid entangled state (polarization and time-bin). Finally, we discuss how the multi-photon gate using XKNLs, qubus beams, and PNR measurement can be reliably performed under the decoherence effect.
Collapse
Affiliation(s)
- Jino Heo
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Min-Sung Kang
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Republic of Korea
| | - Chang-Ho Hong
- National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Hyung-Jin Yang
- Department of Physics, Korea University, Sejong, 339-700, Republic of Korea
| | - Seong-Gon Choi
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Jong-Phil Hong
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
| |
Collapse
|
24
|
Steinlechner F, Ecker S, Fink M, Liu B, Bavaresco J, Huber M, Scheidl T, Ursin R. Distribution of high-dimensional entanglement via an intra-city free-space link. Nat Commun 2017; 8:15971. [PMID: 28737168 PMCID: PMC5527279 DOI: 10.1038/ncomms15971] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 05/17/2017] [Indexed: 11/09/2022] Open
Abstract
Quantum entanglement is a fundamental resource in quantum information processing and its distribution between distant parties is a key challenge in quantum communications. Increasing the dimensionality of entanglement has been shown to improve robustness and channel capacities in secure quantum communications. Here we report on the distribution of genuine high-dimensional entanglement via a 1.2-km-long free-space link across Vienna. We exploit hyperentanglement, that is, simultaneous entanglement in polarization and energy-time bases, to encode quantum information, and observe high-visibility interference for successive correlation measurements in each degree of freedom. These visibilities impose lower bounds on entanglement in each subspace individually and certify four-dimensional entanglement for the hyperentangled system. The high-fidelity transmission of high-dimensional entanglement under real-world atmospheric link conditions represents an important step towards long-distance quantum communications with more complex quantum systems and the implementation of advanced quantum experiments with satellite links. Increasing the dimensionality of entangled states improves robustness and capacity of secure quantum communications, but it requires suitably modified setups. Here the authors report the distribution of high-dimensional polarization and energy-time entangled photons via a 1.2 km-long free-space link.
Collapse
Affiliation(s)
- Fabian Steinlechner
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Sebastian Ecker
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Matthias Fink
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Bo Liu
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.,School of Computer, NUDT, Changsha 410073, China
| | - Jessica Bavaresco
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Marcus Huber
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Thomas Scheidl
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Rupert Ursin
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.,Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
| |
Collapse
|
25
|
Generation of path-polarization hyperentanglement using quasi-phase-matching in quasi-periodic nonlinear photonic crystal. Sci Rep 2017; 7:4954. [PMID: 28694509 PMCID: PMC5504080 DOI: 10.1038/s41598-017-05271-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 05/26/2017] [Indexed: 12/04/2022] Open
Abstract
A compact scheme for the generation of path-polarization entangled photon pairs is proposed by using a quasi-periodic nonlinear photonic crystal to simultaneously accomplish four spontaneous parametric down-conversion processes. Moreover, we report experimental scheme to measure the polarization entanglement and path entanglement separately and theoretically get numerical results that verify some predictions about the hyperentanglement. This method can be expanded for the generation of multi-partite and two-photon path-polarization hyperentanglement in a single quasi-periodic nonlinear photonic crystal structure. This compact quantum light source can be used as a significant ingredient in quantum information science.
Collapse
|
26
|
Hegazy SF, Obayya SSA, Saleh BEA. Orthogonal quasi-phase-matched superlattice for generation of hyperentangled photons. Sci Rep 2017. [PMID: 28646199 PMCID: PMC5482903 DOI: 10.1038/s41598-017-03023-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A crystal superlattice structure featuring nonlinear layers with alternating orthogonal optic axes interleaved with orthogonal poling directions, is shown to generate high-quality hyperentangled photon pairs via orthogonal quasi-phase-matched spontaneous parametric downconversion. We demonstrate that orthogonal quasi-phase matching (QPM) processes in a single nonlinear domain structure correct phase and group-velocity mismatches concurrently. Compared with the conventional two-orthogonal-crystals source and the double-nonlinearity single-crystal source, the orthogonal QPM superlattice is shown to suppress the spatial and temporal distinguishability of the generated photon pairs by several orders of magnitude, depending on the number of layers. This enhanced all-over-the-cone indistinguishability enables the generation of higher fluxes of photon-pairs by means of the combined use of (a) long nonlinear crystal in noncollinear geometry, (b) low coherence-time pumping and ultra-wide-band spectral detection, and (c) focused pumping and over-the-cone detection. While each of these three features is challenging by itself, it is remarkable that the orthogonal QPM superlattice meets all of these challenges without the need for separate spatial or temporal compensation.
Collapse
Affiliation(s)
- Salem F Hegazy
- National Institute of Laser Enhanced Sciences, Cairo University, 12613, Giza, Egypt.,CREOL, The College of Optics & Photonics, University of Central Florida, Orlando, FL, 32816, USA.,Center for Photonics and Smart Materials, Zewail City of Science and Technology, 12588, Giza, Egypt
| | - Salah S A Obayya
- Center for Photonics and Smart Materials, Zewail City of Science and Technology, 12588, Giza, Egypt
| | - Bahaa E A Saleh
- CREOL, The College of Optics & Photonics, University of Central Florida, Orlando, FL, 32816, USA.
| |
Collapse
|
27
|
Zhang W, Ding DS, Sheng YB, Zhou L, Shi BS, Guo GC. Quantum Secure Direct Communication with Quantum Memory. PHYSICAL REVIEW LETTERS 2017. [PMID: 28621985 DOI: 10.1103/physrevlett.118.220501] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Quantum communication provides an absolute security advantage, and it has been widely developed over the past 30 years. As an important branch of quantum communication, quantum secure direct communication (QSDC) promotes high security and instantaneousness in communication through directly transmitting messages over a quantum channel. The full implementation of a quantum protocol always requires the ability to control the transfer of a message effectively in the time domain; thus, it is essential to combine QSDC with quantum memory to accomplish the communication task. In this Letter, we report the experimental demonstration of QSDC with state-of-the-art atomic quantum memory for the first time in principle. We use the polarization degrees of freedom of photons as the information carrier, and the fidelity of entanglement decoding is verified as approximately 90%. Our work completes a fundamental step toward practical QSDC and demonstrates a potential application for long-distance quantum communication in a quantum network.
Collapse
Affiliation(s)
- Wei Zhang
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dong-Sheng Ding
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Bo Sheng
- Key Laboratory of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003, China
| | - Lan Zhou
- Key Laboratory of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003, China
| | - Bao-Sen Shi
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guang-Can Guo
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
28
|
Williams BP, Sadlier RJ, Humble TS. Superdense Coding over Optical Fiber Links with Complete Bell-State Measurements. PHYSICAL REVIEW LETTERS 2017; 118:050501. [PMID: 28211745 DOI: 10.1103/physrevlett.118.050501] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Adopting quantum communication to modern networking requires transmitting quantum information through a fiber-based infrastructure. We report the first demonstration of superdense coding over optical fiber links, taking advantage of a complete Bell-state measurement enabled by time-polarization hyperentanglement, linear optics, and common single-photon detectors. We demonstrate the highest single-qubit channel capacity to date utilizing linear optics, 1.665±0.018, and we provide a full experimental implementation of a hybrid, quantum-classical communication protocol for image transfer.
Collapse
Affiliation(s)
- Brian P Williams
- Quantum Computing Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Ronald J Sadlier
- Quantum Computing Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Travis S Humble
- Quantum Computing Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| |
Collapse
|
29
|
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.
Collapse
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.
| |
Collapse
|
30
|
Wang GY, Ai Q, Ren BC, Li T, Deng FG. Error-detected generation and complete analysis of hyperentangled Bell states for photons assisted by quantum-dot spins in double-sided optical microcavities. OPTICS EXPRESS 2016; 24:28444-28458. [PMID: 27958494 DOI: 10.1364/oe.24.028444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We construct an error-detected block, assisted by the quantum-dot spins in double-sided optical microcavities. With this block, we propose three error-detected schemes for the deterministic generation, the complete analysis, and the complete nondestructive analysis of hyperentangled Bell states in both the polarization and spatial-mode degrees of freedom of two-photon systems. In these schemes, the errors can be detected, which can improve their fidelities largely, far different from other previous schemes assisted by the interaction between the photon and the QD-cavity system. Our scheme for the deterministic generation of hyperentangled two-photon systems can be performed by repeat until success. These features make our schemes more useful in high-capacity quantum communication with hyperentanglement in the future.
Collapse
|
31
|
Experimental realization of entanglement in multiple degrees of freedom between two quantum memories. Nat Commun 2016; 7:13514. [PMID: 27841274 PMCID: PMC5114578 DOI: 10.1038/ncomms13514] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 10/07/2016] [Indexed: 11/18/2022] Open
Abstract
Entanglement in multiple degrees of freedom has many benefits over entanglement in a single one. The former enables quantum communication with higher channel capacity and more efficient quantum information processing and is compatible with diverse quantum networks. Establishing multi-degree-of-freedom entangled memories is not only vital for high-capacity quantum communication and computing, but also promising for enhanced violations of nonlocality in quantum systems. However, there have been yet no reports of the experimental realization of multi-degree-of-freedom entangled memories. Here we experimentally established hyper- and hybrid entanglement in multiple degrees of freedom, including path (K-vector) and orbital angular momentum, between two separated atomic ensembles by using quantum storage. The results are promising for achieving quantum communication and computing with many degrees of freedom. Establishing multi-degree-of-freedom entangled memories is important for high-capacity quantum communications and computing. Here, authors experimentally demonstrate hyper- and hybrid entanglement between two atomic ensembles in multiple degrees of freedom including path and orbital angular momentum.
Collapse
|
32
|
Li XH, Ghose S. Complete hyperentangled Bell state analysis for polarization and time-bin hyperentanglement. OPTICS EXPRESS 2016; 24:18388-18398. [PMID: 27505802 DOI: 10.1364/oe.24.018388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a complete hyperentangled Bell state analysis protocol for two-photon four-qubit states that are simultaneously entangled in the polarization and time-bin degrees of freedom. The 16 hyperentangled states can be unambiguously distinguished via two steps. In the first step, the polarization entangled state is distinguished deterministically and nondestructively with the help of the cross-Kerr nonlinearity. Then, in the second step, the time-bin state is analyzed with the aid of the polarization entanglement. We also discuss the applications of our protocol for quantum information processing. Compared with hyperentanglement in polarization and spatial-mode degrees of freedom, the polarization and time-bin hyperentangled states provide savings in quantum resources since there is no requirement for two spatial modes for each photon. This is the first complete hyperentangled Bell state analysis scheme for polarization and time-bin hyperentangled states, and it can provide new avenues for high-capacity, long-distance quantum communication.
Collapse
|
33
|
Quantum computation based on photonic systems with two degrees of freedom assisted by the weak cross-Kerr nonlinearity. Sci Rep 2016; 6:29939. [PMID: 27424767 PMCID: PMC4947932 DOI: 10.1038/srep29939] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/27/2016] [Indexed: 11/12/2022] Open
Abstract
Most of previous quantum computations only take use of one degree of freedom (DoF) of photons. An experimental system may possess various DoFs simultaneously. In this paper, with the weak cross-Kerr nonlinearity, we investigate the parallel quantum computation dependent on photonic systems with two DoFs. We construct nearly deterministic controlled-not (CNOT) gates operating on the polarization spatial DoFs of the two-photon or one-photon system. These CNOT gates show that two photonic DoFs can be encoded as independent qubits without auxiliary DoF in theory. Only the coherent states are required. Thus one half of quantum simulation resources may be saved in quantum applications if more complicated circuits are involved. Hence, one may trade off the implementation complexity and simulation resources by using different photonic systems. These CNOT gates are also used to complete various applications including the quantum teleportation and quantum superdense coding.
Collapse
|
34
|
Li P, Wang B, Zhang X. High-dimensional encoding based on classical nonseparability. OPTICS EXPRESS 2016; 24:15143-15159. [PMID: 27410666 DOI: 10.1364/oe.24.015143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Based on the formal analogy between classical nonseparability and quantum entanglement, we present a multi-ary encoding protocol exploiting the nonseparability of orbital angular momentum (OAM) and polarization for a hybrid vector beam. Such an encoding can be realized in high-dimensional state space by transforming OAM of the vector beam under the assistance of polarization, which is called "high-dimensional" encoding. It is shown that N-ary encoding using N-dimensional non-separable basis can be obtained by manipulating N/2 different OAM modes, which is equivalent to encoding log2N bits of information. It is also shown that the decoding of vector beams can be realized with very low cross talk. Compared with the encoding protocol transforming OAM modes of scalar beams, our encoding scheme, based on classical nonseparability of vector beams, can encode much more information. This is of great benefit to the optical communication.
Collapse
|
35
|
Liu Q, Wang GY, Ai Q, Zhang M, Deng FG. Complete nondestructive analysis of two-photon six-qubit hyperentangled Bell states assisted by cross-Kerr nonlinearity. Sci Rep 2016; 6:22016. [PMID: 26912172 PMCID: PMC4766504 DOI: 10.1038/srep22016] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/05/2016] [Indexed: 11/28/2022] Open
Abstract
Hyperentanglement, the entanglement in several degrees of freedom (DOFs) of a quantum system, has attracted much attention as it can be used to increase both the channel capacity of quantum communication and its security largely. Here, we present the first scheme to completely distinguish the hyperentangled Bell states of two-photon systems in three DOFs with the help of cross-Kerr nonlinearity without destruction, including two longitudinal momentum DOFs and the polarization DOF. We use cross-Kerr nonlinearity to construct quantum nondemolition detectors which can be used to make a parity-check measurement and analyze Bell states of two-photon systems in different DOFs. Our complete scheme for two-photon six-qubit hyperentangled Bell-state analysis may be useful for the practical applications in quantum information, especially in long-distance high-capacity quantum communication.
Collapse
Affiliation(s)
- Qian Liu
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Guan-Yu Wang
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Qing Ai
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Mei Zhang
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Fu-Guo Deng
- Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
36
|
Complete hyperentangled-Bell-state analysis for photonic qubits assisted by a three-level Λ-type system. Sci Rep 2016; 6:19497. [PMID: 26780930 PMCID: PMC4726112 DOI: 10.1038/srep19497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/15/2015] [Indexed: 11/24/2022] Open
Abstract
Hyperentangled Bell-state analysis (HBSA) is an essential method in high-capacity quantum communication and quantum information processing. Here by replacing the two-qubit controlled-phase gate with the two-qubit SWAP gate, we propose a scheme to distinguish the 16 hyperentangled Bell states completely in both the polarization and the spatial-mode degrees of freedom (DOFs) of two-photon systems. The proposed scheme reduces the use of two-qubit interaction which is fragile and cumbersome, and only one auxiliary particle is required. Meanwhile, it reduces the requirement for initializing the auxiliary particle which works as a temporary quantum memory, and does not have to be actively controlled or measured. Moreover, the state of the auxiliary particle remains unchanged after the HBSA operation, and within the coherence time, the auxiliary particle can be repeatedly used in the next HBSA operation. Therefore, the engineering complexity of our HBSA operation is greatly simplified. Finally, we discuss the feasibility of our scheme with current technologies.
Collapse
|
37
|
Classical hypercorrelation and wave-optics analogy of quantum superdense coding. Sci Rep 2015; 5:18574. [PMID: 26689679 PMCID: PMC4686973 DOI: 10.1038/srep18574] [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: 09/30/2015] [Accepted: 11/20/2015] [Indexed: 11/24/2022] Open
Abstract
We report the first experimental realization of classical hypercorrelation, correlated simultaneously in every degree of freedom (DOF), from observing a Bell-type inequality violation in each DOF: polarization and orbital angular momentum (OAM). Based on such a classical hypercorrelation, we have realized the analogy of quantum superdense coding in classical optics. Comparing it with quantum superdense coding using pairs of photons simultaneously entangled in polarization and OAM, we find that it exhibits many advantages. It is not only very convenient to realize in classical optics, the attainable channel capacity in the experiment for such a superdense coding can also reach 3 bits, which is higher than that (2.8 bits) of usual quantum one. Our findings can not only give novel insight into quantum physics, they may also open a new field of applications in the classical optical information process.
Collapse
|
38
|
Highly efficient hyperentanglement concentration with two steps assisted by quantum swap gates. Sci Rep 2015; 5:16444. [PMID: 26552898 PMCID: PMC4639739 DOI: 10.1038/srep16444] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 10/12/2015] [Indexed: 12/01/2022] Open
Abstract
We present a two-step hyperentanglement concentration protocol (hyper-ECP) for polarization-spatial hyperentangled Bell states based on the high-capacity character of hyperentanglement resorting to the swap gates, which is used to obtain maximally hyperentangled states from partially hyperentangled pure states in long-distance quantum communication. The swap gate, which is constructed with the giant optical circular birefringence (GOCB) of a diamond nitrogen-vacancy (NV) center embedded in a photonic crystal cavity, can be used to transfer the information in one degree of freedom (DOF) between photon systems. By transferring the useful information between hyperentangled photon pairs, more photon pairs in maximally hyperentangled state can be obtained in our hyper-ECP, and the success probability of the hyper-ECP is greatly improved. Moreover, we show that the high-fidelity quantum gate operations can be achieved by mapping the infidelities to heralded losses even in the weak coupling regime.
Collapse
|
39
|
Two-step complete polarization logic Bell-state analysis. Sci Rep 2015; 5:13453. [PMID: 26307327 PMCID: PMC4549687 DOI: 10.1038/srep13453] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 07/28/2015] [Indexed: 11/30/2022] Open
Abstract
The Bell state plays a significant role in the fundamental tests of quantum mechanics, such as the nonlocality of the quantum world. The Bell-state analysis is of vice importance in quantum communication. Existing Bell-state analysis protocols usually focus on the Bell-state encoding in the physical qubit directly. In this paper, we will describe an alternative approach to realize the near complete logic Bell-state analysis for the polarized concatenated Greenberger-Horne-Zeilinger (C-GHZ) state with two logic qubits. We show that the logic Bell-state can be distinguished in two steps with the help of the parity-check measurement (PCM) constructed by the cross-Kerr nonlinearity. This approach can be also used to distinguish arbitrary C-GHZ state with N logic qubits. As both the recent theoretical and experiment work showed that the C-GHZ state has its robust feature in practical noisy environment, this protocol may be useful in future long-distance quantum communication based on the logic-qubit entanglement.
Collapse
|
40
|
Li XH, Ghose S. Efficient hyperconcentration of nonlocal multipartite entanglement via the cross-Kerr nonlinearity. OPTICS EXPRESS 2015; 23:3550-3562. [PMID: 25836208 DOI: 10.1364/oe.23.003550] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We propose two schemes for concentration of hyperentanglement of nonlocal multipartite states which are simultaneously entangled in the polarization and spatial modes. One scheme uses an auxiliary single-photon state prepared according to the parameters of the less-entangled states. The other scheme uses two less-entangled states with unknown parameters to distill the maximal hyperentanglement. The procrustean concentration is realized by two parity check measurements in both the two degrees of freedom. Nondestructive quantum nondemolition detectors based on cross-Kerr nonlinearity are used to implement the parity check, which makes the unsuccessful instances reusable in the next concentration round. The success probabilities in both schemes can be made to approach unity by iteration. Moreover, in both schemes only one of the N parties has to perform the parity check measurements. Our schemes are efficient and useful for quantum information processing involving hyperentanglement.
Collapse
|
41
|
Ding DS, Zhang W, Zhou ZY, Shi S, Xiang GY, Wang XS, Jiang YK, Shi BS, Guo GC. Quantum storage of orbital angular momentum entanglement in an atomic ensemble. PHYSICAL REVIEW LETTERS 2015; 114:050502. [PMID: 25699427 DOI: 10.1088/1361-6455/aa9b95] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 05/28/2023]
Abstract
Constructing a quantum memory for a photonic entanglement is vital for realizing quantum communication and network. Because of the inherent infinite dimension of orbital angular momentum (OAM), the photon's OAM has the potential for encoding a photon in a high-dimensional space, enabling the realization of high channel capacity communication. Photons entangled in orthogonal polarizations or optical paths had been stored in a different system, but there have been no reports on the storage of a photon pair entangled in OAM space. Here, we report the first experimental realization of storing an entangled OAM state through the Raman protocol in a cold atomic ensemble. We reconstruct the density matrix of an OAM entangled state with a fidelity of 90.3%±0.8% and obtain the Clauser-Horne-Shimony-Holt inequality parameter S of 2.41±0.06 after a programed storage time. All results clearly show the preservation of entanglement during the storage.
Collapse
Affiliation(s)
- Dong-Sheng Ding
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Wei Zhang
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhi-Yuan Zhou
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shuai Shi
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guo-Yong Xiang
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xi-Shi Wang
- State Key Laboratory of Fire Science, University of Science & Technology of China, Hefei, Anhui 230026, China
| | - Yun-Kun Jiang
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350002, People's Republic of China
| | - Bao-Sen Shi
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guang-Can Guo
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
42
|
Sheng YB, Zhou L. Deterministic entanglement distillation for secure double-server blind quantum computation. Sci Rep 2015; 5:7815. [PMID: 25588565 PMCID: PMC4295105 DOI: 10.1038/srep07815] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 12/02/2014] [Indexed: 11/09/2022] Open
Abstract
Blind quantum computation (BQC) provides an efficient method for the client who does not have enough sophisticated technology and knowledge to perform universal quantum computation. The single-server BQC protocol requires the client to have some minimum quantum ability, while the double-server BQC protocol makes the client's device completely classical, resorting to the pure and clean Bell state shared by two servers. Here, we provide a deterministic entanglement distillation protocol in a practical noisy environment for the double-server BQC protocol. This protocol can get the pure maximally entangled Bell state. The success probability can reach 100% in principle. The distilled maximally entangled states can be remaind to perform the BQC protocol subsequently. The parties who perform the distillation protocol do not need to exchange the classical information and they learn nothing from the client. It makes this protocol unconditionally secure and suitable for the future BQC protocol.
Collapse
Affiliation(s)
- Yu-Bo Sheng
- 1] Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003, China [2] Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003, China
| | - Lan Zhou
- 1] Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003, China [2] College of Mathematics &Physics, Nanjing University of Posts and Telecommunications, Nanjing 210003, China
| |
Collapse
|
43
|
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.
Collapse
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
| |
Collapse
|
44
|
Ren BC, Long GL. General hyperentanglement concentration for photon systems assisted by quantum-dot spins inside optical microcavities. OPTICS EXPRESS 2014; 22:6547-6561. [PMID: 24664003 DOI: 10.1364/oe.22.006547] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Hyperentanglement is a promising resource in quantum information processing, especially for increasing the channel capacity of long-distance quantum communication. Here we present a general hyper-entanglement concentration protocol (hyper-ECP) for nonlocal partially hyperentangled Bell states that decay with the interrelationship between the polarization and the spatial-mode degrees of freedom of two-photon systems, which is not taken into account in other hyper-ECPs, resorting to the optical property of the quantum-dot spins inside one-side optical microcavities. We show that the success probability of our hyper-ECP is largely increased by iteration of the hyper-ECP process. Our hyper-ECP can be straightforwardly generalized to distill nonlocal maximally hyperentangled N-photon Greenberger-Horne-Zeilinger (GHZ) states from arbitrary partially hyperentangled GHZ-class states.
Collapse
|
45
|
Megidish E, Halevy A, Shacham T, Dvir T, Dovrat L, Eisenberg HS. Entanglement swapping between photons that have never coexisted. PHYSICAL REVIEW LETTERS 2013; 110:210403. [PMID: 23745845 DOI: 10.1103/physrevlett.110.210403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Indexed: 06/02/2023]
Abstract
The role of the timing and order of quantum measurements is not just a fundamental question of quantum mechanics, but also a puzzling one. Any part of a quantum system that has finished evolving can be measured immediately or saved for later, without affecting the final results, regardless of the continued evolution of the rest of the system. In addition, the nonlocality of quantum mechanics, as manifested by entanglement, does not apply only to particles with spacelike separation, but also to particles with timelike separation. In order to demonstrate these principles, we generated and fully characterized an entangled pair of photons that have never coexisted. Using entanglement swapping between two temporally separated photon pairs, we entangle one photon from the first pair with another photon from the second pair. The first photon was detected even before the other was created. The observed two-photon state demonstrates that entanglement can be shared between timelike separated quantum systems.
Collapse
Affiliation(s)
- E Megidish
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | | | | | | | | | | |
Collapse
|
46
|
Pavičić M. Near-deterministic discrimination of all Bell states with linear optics. PHYSICAL REVIEW LETTERS 2011; 107:080403. [PMID: 21929149 DOI: 10.1103/physrevlett.107.080403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Indexed: 05/31/2023]
Abstract
For a reliable implementation of quantum teleportation, a near-deterministic (close to 100%) discrimination of all four Bell states of entangled qubits is required. One can carry it out with linear optical elements only if conditional dynamics are allowed. Here we present a setup in which we repeatedly disentangle and reentangle photons in three of four states, so as to separate photons in one of them, conditioned on keeping the other two at bay. The efficiency of a realistic implementation of our setup with current technology is over 90% for an ideal source of photons on demand.
Collapse
Affiliation(s)
- Mladen Pavičić
- Chair of Physics, Faculty of Civil Engineering, University of Zagreb, Zagreb 10001, Croatia.
| |
Collapse
|
47
|
Halevy A, Megidish E, Shacham T, Dovrat L, Eisenberg HS. Projection of two biphoton qutrits onto a maximally entangled state. PHYSICAL REVIEW LETTERS 2011; 106:130502. [PMID: 21517363 DOI: 10.1103/physrevlett.106.130502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Indexed: 05/30/2023]
Abstract
Bell state measurements, in which two quantum bits are projected onto a maximally entangled state, are an essential component of quantum information science. We propose and experimentally demonstrate the projection of two quantum systems with three states (qutrits) onto a generalized maximally entangled state. Each qutrit is represented by the polarization of a pair of indistinguishable photons-a biphoton. The projection is a joint measurement on both biphotons using standard linear optics elements. This demonstration enables the realization of quantum information protocols with qutrits, such as teleportation and entanglement swapping.
Collapse
Affiliation(s)
- A Halevy
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | | | | | | | | |
Collapse
|
48
|
Barreiro JT, Wei TC, Kwiat PG. Remote preparation of single-photon "hybrid" entangled and vector-polarization States. PHYSICAL REVIEW LETTERS 2010; 105:030407. [PMID: 20867752 DOI: 10.1103/physrevlett.105.030407] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Indexed: 05/29/2023]
Abstract
Quantum teleportation faces increasingly demanding requirements for transmitting large or even entangled systems. However, knowledge of the state to be transmitted eases its reconstruction, resulting in a protocol known as remote state preparation. A number of experimental demonstrations to date have been restricted to single-qubit systems. We report the remote preparation of two-qubit "hybrid" entangled states, including a family of vector-polarization beams. Our single-photon states are encoded in the photon spin and orbital angular momentum. We reconstruct the states by spin-orbit state tomography and transverse polarization tomography. The high fidelities achieved for the vector-polarization states opens the door to optimal coupling of down-converted photons to other physical systems, such as an atom, as required for scalable quantum networks, or plasmons in photonic nanostructures.
Collapse
Affiliation(s)
- Julio T Barreiro
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | | | | |
Collapse
|
49
|
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.
Collapse
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
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
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.
Collapse
Affiliation(s)
- Alessandro Rossi
- Dipartimento di Fisica, Sapienza Università di Roma, Roma 00185, Italy
| | | | | | | | | |
Collapse
|