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Dong MX, Zhang WH, Zeng L, Ye YH, Li DC, Guo GC, Ding DS, Shi BS. Highly Efficient Storage of 25-Dimensional Photonic Qudit in a Cold-Atom-Based Quantum Memory. PHYSICAL REVIEW LETTERS 2023; 131:240801. [PMID: 38181137 DOI: 10.1103/physrevlett.131.240801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 11/16/2023] [Indexed: 01/07/2024]
Abstract
Building an efficient quantum memory in high-dimensional Hilbert spaces is one of the fundamental requirements for establishing high-dimensional quantum repeaters, where it offers many advantages over two-dimensional quantum systems, such as a larger information capacity and enhanced noise resilience. To date, it remains a challenge to develop an efficient high-dimensional quantum memory. Here, we experimentally realize a quantum memory that is operational in Hilbert spaces of up to 25 dimensions with a storage efficiency of close to 60% and a fidelity of 84.2±0.6%. The proposed approach exploits the spatial-mode-independent interaction between atoms and photons which are encoded in transverse-size-invariant vortex modes. In particular, our memory features uniform storage efficiency and low crosstalk disturbance for 25 individual spatial modes of photons, thus allowing the storing of qudit states programmed from 25 eigenstates within the high-dimensional Hilbert spaces. These results have great prospects for the implementation of long-distance high-dimensional quantum networks and quantum information processing.
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Affiliation(s)
- Ming-Xin Dong
- Key Laboratory of Quantum Information, 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
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Materials Engineering, Hefei Normal University, Hefei, Anhui 230601, China
| | - Wei-Hang Zhang
- Key Laboratory of Quantum Information, 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
| | - Lei Zeng
- Key Laboratory of Quantum Information, 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
| | - Ying-Hao Ye
- Key Laboratory of Quantum Information, 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
| | - Da-Chuang Li
- School of Physics and Materials Engineering, Hefei Normal University, Hefei, Anhui 230601, China
| | - Guang-Can Guo
- Key Laboratory of Quantum Information, 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
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Dong-Sheng Ding
- Key Laboratory of Quantum Information, 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
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Bao-Sen Shi
- Key Laboratory of Quantum Information, 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
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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2
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Ma L, Lei X, Cheng J, Yan Z, Jia X. Deterministic manipulation of steering between distant quantum network nodes. OPTICS EXPRESS 2023; 31:8257-8266. [PMID: 36859941 DOI: 10.1364/oe.479182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Multipartite Einstein-Podolsky-Rosen (EPR) steering is a key resource in a quantum network. Although EPR steering between spatially separated regions of ultracold atomic systems has been observed, deterministic manipulation of steering between distant quantum network nodes is required for a secure quantum communication network. Here, we propose a feasible scheme to deterministically generate, store, and manipulate one-way EPR steering between distant atomic cells by a cavity-enhanced quantum memory approach. While optical cavities effectively suppress the unavoidable noises in electromagnetically induced transparency, three atomic cells are in a strong Greenberger-Horne-Zeilinger state by faithfully storing three spatially separated entangled optical modes. In this way, the strong quantum correlation of atomic cells guarantees one-to-two node EPR steering is achieved, and can perserve the stored EPR steering in these quantum nodes. Furthermore, the steerability can be actively manipulated by the temperature of the atomic cell. This scheme provides the direct reference for experimental implementation for one-way multipartite steerable states, which enables an asymmetric quantum network protocol.
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3
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Zhu TX, Liu C, Jin M, Su MX, Liu YP, Li WJ, Ye Y, Zhou ZQ, Li CF, Guo GC. On-Demand Integrated Quantum Memory for Polarization Qubits. PHYSICAL REVIEW LETTERS 2022; 128:180501. [PMID: 35594095 DOI: 10.1103/physrevlett.128.180501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
Photonic polarization qubits are widely used in quantum computation and quantum communication due to the robustness in transmission and the easy qubit manipulation. An integrated quantum memory for polarization qubits is a useful building block for large-scale integrated quantum networks. However, on-demand storing polarization qubits in an integrated quantum memory is a long-standing challenge due to the anisotropic absorption of solids and the polarization-dependent features of microstructures. Here we demonstrate a reliable on-demand quantum memory for polarization qubits, using a depressed-cladding waveguide fabricated in a ^{151}Eu^{3+}:Y_{2}SiO_{5} crystal. The site-2 ^{151}Eu^{3+} ions in Y_{2}SiO_{5} crystal provides a near-uniform absorption for arbitrary polarization states and a new pump sequence is developed to prepare a wideband and enhanced absorption profile. A fidelity of 99.4±0.6% is obtained for the qubit storage process with an input of 0.32 photons per pulse, together with a storage bandwidth of 10 MHz. This reliable integrated quantum memory for polarization qubits reveals the potential for use in the construction of integrated quantum networks.
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Affiliation(s)
- Tian-Xiang Zhu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Chao Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Ming Jin
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Ming-Xu Su
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Yu-Ping Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Wen-Juan Li
- Center for Micro and Nanoscale Research and Fabrication, University of Science and Technology of China, Hefei 230026, China
| | - Yang Ye
- Center for Micro and Nanoscale Research and Fabrication, University of Science and Technology of China, Hefei 230026, China
| | - Zong-Quan Zhou
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Chuan-Feng Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
| | - Guang-Can Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
- Hefei National Laboratory, Hefei 230088, China
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4
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Hsu H, Cheng CY, Shiu JS, Chen LC, Chen YF. Quantum fidelity of electromagnetically induced transparency: the full quantum theory. OPTICS EXPRESS 2022; 30:2097-2111. [PMID: 35209357 DOI: 10.1364/oe.448334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
We present a full quantum model to study the fidelity of single photons with different quantum states propagating in a medium exhibiting electromagnetically induced transparency (EIT). By using the general reservoir theory, we can calculate the quantum state of the transmitted probe photons that reveal the EIT phenomenon predicted by semiclassical theory while reflecting the influence of the quantum fluctuations of the strong coupling field. Our study shows that the coupling field fluctuations not only change the quantum state of the probe photons, but also slightly affect its transmittance. Moreover, we demonstrate that the squeezed coupling field can enhance the influence of its fluctuations on the quantum state of the probe photons, which means that the EIT effect can be manipulated by controlling the quantum state properties of the coupling field. The full quantum theory in this paper is suitable for studying quantum systems related to the EIT mechanism that would allow us to examine various quantum effects in EIT-based systems from a full quantum perspective.
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5
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Yu Y, Sun PF, Zhang YZ, Bai B, Fang YQ, Luo XY, An ZY, Li J, Zhang J, Xu F, Bao XH, Pan JW. Measurement-Device-Independent Verification of a Quantum Memory. PHYSICAL REVIEW LETTERS 2021; 127:160502. [PMID: 34723577 DOI: 10.1103/physrevlett.127.160502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
In this Letter we report an experiment that verifies an atomic-ensemble quantum memory via a measurement-device-independent scheme. A single photon generated via Rydberg blockade in one atomic ensemble is stored in another atomic ensemble via electromagnetically induced transparency. After storage for a long duration, this photon is retrieved and interfered with a second photon to perform a joint Bell-state measurement (BSM). The quantum state for each photon is chosen based on a quantum random number generator, respectively, in each run. By evaluating correlations between the random states and BSM results, we certify that our memory is genuinely entanglement preserving.
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Affiliation(s)
- Yong Yu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Peng-Fei 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Zhe 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bing Bai
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Qiang Fang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xi-Yu Luo
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zi-Ye An
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jun 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jun 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Feihu 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao-Hui Bao
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, 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; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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6
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Qiu TH, Li H, Xie M, Liu Q, Ma HY, Xu R. Efficient all-optical router and beam splitter for light with orbital angular momentum. OPTICS EXPRESS 2020; 28:19750-19759. [PMID: 32672245 DOI: 10.1364/oe.395984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
We propose an efficient scheme for realizing all-optical router or beam splitter (BS) by employing a double tripod-type atomic system, where the ground levels are coupled by two additional intensity-dependent weak microwave fields. We show that the high-dimensional probe field encoded in a degree of freedom of orbital angular momentum can be stored, retrieved, and manipulated. Due to the constructive or destructive interference between the introduced microwave fields and the atomic spin coherence, the generated stationary light pulses and the retrieved probe fields can be increased or decreased with high efficiency and fidelity in a controllable manner. On the basis of the results and a general extension, a tunable all-optical router or BS, which can split a high-dimensional probe field into two or more ones, can be achieved by actively operating the controlling fields and the microwave fields. The current scheme, integrating multiple functions and showing excellent performance, could greatly enhance the tunability and capacity for the all-optical information processing.
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7
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Li C, Jiang N, Wu YK, Chang W, Pu YF, Zhang S, Duan LM. Quantum Communication between Multiplexed Atomic Quantum Memories. PHYSICAL REVIEW LETTERS 2020; 124:240504. [PMID: 32639803 DOI: 10.1103/physrevlett.124.240504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
The use of multiplexed atomic quantum memories (MAQM) can significantly enhance the efficiency to establish entanglement in a quantum network. In the previous experiments, individual elements of a quantum network, such as the generation, storage, and transmission of quantum entanglement have been demonstrated separately. Here we report an experiment to show the compatibility and integration of these basic operations. Specifically, we generate photon-atom entanglement from any chosen pair of memory cells in a 6×5 MAQM, convert the spin-wave to time-bin photonic excitation after a controllable storage time, and then store and retrieve the photon in a second MAQM for another controllable storage time. The preservation of quantum information in this process is verified by measuring the state fidelity. We also demonstrate that higher dimension quantum states can be transferred between the two distant MAQMs.
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Affiliation(s)
- C Li
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - N Jiang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Y-K Wu
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - W Chang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Y-F Pu
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - S Zhang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - L-M Duan
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
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8
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Lee SM, Lee SW, Jeong H, Park HS. Quantum Teleportation of Shared Quantum Secret. PHYSICAL REVIEW LETTERS 2020; 124:060501. [PMID: 32109109 DOI: 10.1103/physrevlett.124.060501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
Quantum teleportation is a fundamental building block of quantum communications and quantum computations, transferring quantum states between distant physical entities. In the context of quantum secret sharing, the teleportation of quantum information shared by multiple parties without concentrating the information at any place is essential, and this cannot be realized by any previous scheme. We propose and experimentally demonstrate a novel teleportation protocol that enables one to perform this task. It is jointly performed by distributed participants, while none of them can fully access the information. Our scheme can be extended to arbitrary numbers of senders and receivers and to fault-tolerant quantum networks by incorporating error-correction codes.
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Affiliation(s)
- Sang Min Lee
- Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Seung-Woo Lee
- Quantum Universe Center, Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - Hyunseok Jeong
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, South Korea
| | - Hee Su Park
- Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
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9
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Gyongyosi L, Imre S. Optimizing High-Efficiency Quantum Memory with Quantum Machine Learning for Near-Term Quantum Devices. Sci Rep 2020; 10:135. [PMID: 31924814 PMCID: PMC6954268 DOI: 10.1038/s41598-019-56689-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/12/2019] [Indexed: 11/09/2022] Open
Abstract
Quantum memories are a fundamental of any global-scale quantum Internet, high-performance quantum networking and near-term quantum computers. A main problem of quantum memories is the low retrieval efficiency of the quantum systems from the quantum registers of the quantum memory. Here, we define a novel quantum memory called high-retrieval-efficiency (HRE) quantum memory for near-term quantum devices. An HRE quantum memory unit integrates local unitary operations on its hardware level for the optimization of the readout procedure and utilizes the advanced techniques of quantum machine learning. We define the integrated unitary operations of an HRE quantum memory, prove the learning procedure, and evaluate the achievable output signal-to-noise ratio values. We prove that the local unitaries of an HRE quantum memory achieve the optimization of the readout procedure in an unsupervised manner without the use of any labeled data or training sequences. We show that the readout procedure of an HRE quantum memory is realized in a completely blind manner without any information about the input quantum system or about the unknown quantum operation of the quantum register. We evaluate the retrieval efficiency of an HRE quantum memory and the output SNR (signal-to-noise ratio). The results are particularly convenient for gate-model quantum computers and the near-term quantum devices of the quantum Internet.
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Affiliation(s)
- Laszlo Gyongyosi
- School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, UK.
- Department of Networked Systems and Services, Budapest University of Technology and Economics, Budapest, H-1117, Hungary.
- MTA-BME Information Systems Research Group, Hungarian Academy of Sciences, Budapest, H-1051, Hungary.
| | - Sandor Imre
- Department of Networked Systems and Services, Budapest University of Technology and Economics, Budapest, H-1117, Hungary
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10
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Wen Y, Zhou P, Xu Z, Yuan L, Wang M, Wang S, Chen L, Wang H. Cavity-enhanced and long-lived optical memories for two orthogonal polarizations in cold atoms. OPTICS EXPRESS 2020; 28:360-368. [PMID: 32118964 DOI: 10.1364/oe.376962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
The storage and retrieval efficiency (SRE) and lifetime of optical quantum memories are two key performance indicators for scaling up quantum information processing. Here, we experimentally demonstrate a cavity-enhanced long-lived optical memory for two polarizations in a cold atomic ensemble. Using electromagnetically induced-transparency (EIT) dynamics, we demonstrate the storages of left-circularly and right-circularly polarized signal light pulses in the atoms, respectively. By making the signal and control beams collinearly pass through the atoms and storing the two polarizations of the signal light as two magnetic-field-insensitive spin waves, we achieve a long-lived (3.5 ms) memory. By placing a low-finesse optical ring cavity around the cold atoms, the coupling between the signal light and the atoms is enhanced, which leads to an increase in SRE. The presented cavity-enhanced storage shows that the SRE is ∼30%, corresponding to an intrinsic SRE of ∼45%.
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11
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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.
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12
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Xie Z, Luo KH, Chang KC, Panoiu NC, Herrmann H, Silberhorn C, Wong CW. Efficient C-band single-photon upconversion with chip-scale Ti-indiffused pp-LiNbO 3 waveguides. APPLIED OPTICS 2019; 58:5910-5915. [PMID: 31503905 DOI: 10.1364/ao.58.005910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/27/2019] [Indexed: 06/10/2023]
Abstract
Frequency upconversion for single photons at telecom wavelengths is important to simultaneously meet the different wavelength requirements for long-distance communications and quantum memories in a quantum nodal network. It also enables the detection for the telecom "flying qubit" photons with silicon-based efficient single-photon detectors with low dark count (DC) rates. Here, we demonstrate the frequency upconversion of attenuated single photons, using a low-loss titanium-indiffused periodically poled lithium niobate waveguide, pumped with a readily available erbium-doped fiber amplifier in the L-band. Internal and conversion efficiencies up to 84.4% and 49.9% have been achieved, respectively. The DC rates are suppressed down to 44 kHz at 13.9% end-to-end quantum efficiency (including full conversion and detection), enabled by our long-wavelength pump configuration and narrow 3.5-GHz bandpass filtering.
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13
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Lachman L, Straka I, Hloušek J, Ježek M, Filip R. Faithful Hierarchy of Genuine n-Photon Quantum Non-Gaussian Light. PHYSICAL REVIEW LETTERS 2019; 123:043601. [PMID: 31491243 DOI: 10.1103/physrevlett.123.043601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/20/2019] [Indexed: 06/10/2023]
Abstract
Light is an essential tool for connections between quantum devices and for diagnostic processes in quantum technology. Both applications deal with advanced nonclassical states beyond Gaussian coherent and squeezed states. Current development requires a loss-tolerant diagnostic of such nonclassical aspects. We propose and experimentally verify a faithful hierarchy of genuine n-photon quantum non-Gaussian light. We conclusively witnessed three-photon quantum non-Gaussian light in the experiment. Measured data demonstrate a direct applicability of the hierarchy for a large class of real states.
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Affiliation(s)
- Lukáš Lachman
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Ivo Straka
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Josef Hloušek
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Miroslav Ježek
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Radim Filip
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
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14
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Zhao TM, Ihn YS, Kim YH. Direct Generation of Narrow-band Hyperentangled Photons. PHYSICAL REVIEW LETTERS 2019; 122:123607. [PMID: 30978083 DOI: 10.1103/physrevlett.122.123607] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Indexed: 06/09/2023]
Abstract
In quantum communication and photonic quantum information processing, the requirement of quantum repeaters and quantum memory often imposes a strict bandwidth prerequisite for the entangled photons. At the same time, there is ever more increasing demand for entangling more degrees of freedom, i.e., hyperentanglement, for a photon pair. In this Letter, we report the direct generation of narrow-band orbital angular momentum (OAM) and polarization hyperentangled photons from cold atoms. The narrow-band photon pair is naturally entangled in polarization and OAM, in addition to time-frequency, degrees of freedom due to spin and orbital angular momentum conservation conditions in the spontaneous four-wave mixing process in a cold atom ensemble. The narrow-band hyperentangled photon pair source reported here is expected to play important roles in quantum memory-based long-distance quantum communication.
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Affiliation(s)
- Tian-Ming Zhao
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Yong Sup Ihn
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Yoon-Ho Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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15
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Liu HY, Zhang R, Xu P, Xie ZD, Gong YX, Zhu SN. Compact generation of a two-photon multipath Dicke state from a single χ (2) nonlinear photonic crystal. OPTICS LETTERS 2019; 44:239-242. [PMID: 30644870 DOI: 10.1364/ol.44.000239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
Multipartite quantum entanglement is a powerful resource for enriching the functionality of quantum computation and quantum communication. In this Letter, we propose a new method to generate a two-photon multipath Dicke state with concurrent spontaneous parametric downconversion processes from a single periodically poled nonlinear photonic crystal. We design the poling structure to produce a three-path Dicke state where three quasi-phase-matching conditions are fulfilled simultaneously by a hybrid one- and two-dimensionally poled nonlinear photonic crystal. We use genuine multipartite entanglement concurrence to quantify the entanglement of the Dicke state. Using a more complicated poling configuration like multiple-periodically poled two-dimensional nonlinear photonic crystal, we can also produce four-path, five-path, or multipath Dicke states by a single crystal. The multiple-periodically poled two-dimensional nonlinear photonic crystal provides a new method, to the best of our knowledge, for the integrated generation of multipartite quantum light sources.
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16
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Zheltikov AM. Enhanced-contrast optical readout in ultrafast broadband Raman quantum memories. Sci Rep 2018; 8:13774. [PMID: 30213955 PMCID: PMC6137051 DOI: 10.1038/s41598-018-31226-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 08/03/2018] [Indexed: 11/09/2022] Open
Abstract
The signal-to-noise contrast of the optical readout in broadband Raman quantum memories is analyzed as a function of the pulse widths and phase properties of tailored optical field waveforms used to write in and read out broadband photon wave packets. Based on this analysis, we quantify the tradeoff between the readout contrast and the speed of such memories. Off-resonance coherent four-wave mixing is shown to provide a source of noise photons, lowering the readout contrast in broadband Raman quantum memories. This noise cannot be suppressed by phase matching, but can be radically reduced with a suitable polarization arrangement and proper field-waveform tailoring.
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Affiliation(s)
- A M Zheltikov
- Department of Physics and Astronomy, Texas A&M University, College Station, 77843, Texas, USA.
- Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia.
- Russian Quantum Center, Skolkovo, Moscow Region, 143025, Russia.
- Kazan Quantum Center, A.N. Tupolev Kazan National Research Technical University, Kazan, 420126, Russia.
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17
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Ham BS. A wavelength-convertible quantum memory: Controlled echo. Sci Rep 2018; 8:10675. [PMID: 30013123 PMCID: PMC6048175 DOI: 10.1038/s41598-018-28776-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/29/2018] [Indexed: 11/09/2022] Open
Abstract
Quantum coherence control is reinvestigated for a new physical insight in quantum nonlinear optics and applied for a wavelength-convertible quantum memory in a solid ensemble whose spin states are inhomogeneously broadened. Unlike typical atomic media whose spin decays are homogeneous, a spin inhomogeneously broadened solid ensemble requires a counter-intuitive quantum coherence control to avoid spontaneous emission-caused quantum noises. Such a quantum coherence control in a solid ensemble satisfying both near perfect retrieval efficiency and ultralong photon storage offers a solid framework to quantum repeaters, scalable qubit generations, quantum cryptography, and highly sensitive magnetometry. Here, the basic physics of the counter-intuitive quantum coherence control is presented not only for a fundamental understanding of collective ensemble phase control but also for a coherence conversion mechanism between optical and spin states involving Raman rephasing.
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Affiliation(s)
- Byoung S Ham
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Chumdangwagi-ro, Buk-gu, Gwangju, 61005, South Korea.
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18
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Qiu TH, Ma HY, Xia LX. Efficient images storage via modulating the atomic spin coherence in a N-type system. OPTICS EXPRESS 2018; 26:17739-17747. [PMID: 30114059 DOI: 10.1364/oe.26.017739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
A four-level N-type cold atomic system is proposed for optimizing images storage based on the electromagnetically induced transparency (EIT). Both analytical analysis and numerical simulation clearly show that the application, during the storage time, of an additional intensity-modulated signal field and an additional microwave field can impose an intensity and a phase-dependent factors on the atomic spin coherence in a controlled manner, then the amplitude of the retrieved images can be increased or decreased with an enhancement in the visibility. Our results are very promising for the realization of all-optical information processing of images coherently stored in EIT media in the future.
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19
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Ma L, Slattery O, Tang X. Noise Reduction in Optically Controlled Quantum Memory. MODERN PHYSICS LETTERS. B, CONDENSED MATTER PHYSICS, STATISTICAL PHYSICS, APPLIED PHYSICS 2018; 32:1830001. [PMID: 38903851 PMCID: PMC11187979 DOI: 10.1142/s0217984918300016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Quantum memory is an essential device for quantum communications systems and quantum computers. An important category of quantum memory, called Optically controlled quantum memory, uses a strong classical beam to control the storage and re-emission of a single photon signal through an atomic ensemble. The residual light from the strong classical control beam can cause severe noise and degrade the system performance significantly. Efficiently suppressing this noise is required for the successful implementation of optically controlled quantum memories. In this paper, we briefly review the latest and most common approaches to quantum memory and discuss the various noise reduction techniques used in implementing them.
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Affiliation(s)
- Lijun Ma
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899, USA
| | - Oliver Slattery
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899, USA
| | - Xiao Tang
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899, USA
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20
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Abstract
Based on electromagnetically induced transparency (EIT), we investigate an all-optical grating structure to realize polarization-dependent multiple beam splitting in the Raman-Nath limit. To optimize the grating performance, higher excited state [e.g., nS1/2 (n ≥ 6)] of ultracold 87Rb atoms is employed to construct a five-level Ξ-Λ system sharing one common populated ground state. A principal advantage of our proposed scheme is that the σ± components of a linearly polarized weak probe field can be decoupled and thus be independently diffracted with high efficiency in both one and two dimensions by exploiting different quasi-standing waves as the two strong coupling fields in the Ξ and Λ configurations. Such an all-optical polarization-sensitive operation could greatly enhance the tunability and capacity of all-optical multiplexing, interconnecting, and networking in free space for both classical and quantum applications.
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21
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Highly-efficient quantum memory for polarization qubits in a spatially-multiplexed cold atomic ensemble. Nat Commun 2018; 9:363. [PMID: 29371593 PMCID: PMC5785556 DOI: 10.1038/s41467-017-02775-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/27/2017] [Indexed: 11/08/2022] Open
Abstract
Quantum memory for flying optical qubits is a key enabler for a wide range of applications in quantum information. A critical figure of merit is the overall storage and retrieval efficiency. So far, despite the recent achievements of efficient memories for light pulses, the storage of qubits has suffered from limited efficiency. Here we report on a quantum memory for polarization qubits that combines an average conditional fidelity above 99% and efficiency around 68%, thereby demonstrating a reversible qubit mapping where more information is retrieved than lost. The qubits are encoded with weak coherent states at the single-photon level and the memory is based on electromagnetically-induced transparency in an elongated laser-cooled ensemble of cesium atoms, spatially multiplexed for dual-rail storage. This implementation preserves high optical depth on both rails, without compromise between multiplexing and storage efficiency. Our work provides an efficient node for future tests of quantum network functionalities and advanced photonic circuits. Future quantum networks will require quantum memories with effective storage-and-retrieval capabilities. Here, the authors use electromagnetically-induced transparency in a high optical-depth, spatially-multiplexed cold atom ensemble to store and retrieve polarization qubits with high efficiency.
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22
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Manzoni MT, Moreno-Cardoner M, Asenjo-Garcia A, Porto JV, Gorshkov AV, Chang DE. Optimization of photon storage fidelity in ordered atomic arrays. NEW JOURNAL OF PHYSICS 2018; 20:10.1088/1367-2630/aadb74. [PMID: 31555054 PMCID: PMC6760042 DOI: 10.1088/1367-2630/aadb74] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A major application for atomic ensembles consists of a quantum memory for light, in which an optical state can be reversibly converted to a collective atomic excitation on demand. There exists a well-known fundamental bound on the storage error, when the ensemble is describable by a continuous medium governed by the Maxwell-Bloch equations. However, these equations are semi-phenomenological, as they treat emission of the atoms into other directions other than the mode of interest as being independent. On the other hand, in systems such as dense, ordered atomic arrays, atoms interact with each other strongly and spatial interference of the emitted light might be exploited to suppress emission into unwanted directions, thereby enabling improved error bounds. Here, we develop a general formalism that fully accounts for spatial interference, and which finds the maximum storage efficiency for a single photon with known spatial input mode into a collection of atoms with discrete, known positions. As an example, we apply this technique to study a finite two-dimensional square array of atoms. We show that such a system enables a storage error that scales with atom number N a like ∼ ( log N a ) 2 ∕ N a 2 , and that, remarkably, an array of just 4 × 4 atoms in principle allows for an error of less than 1%, which is comparable to a disordered ensemble with an optical depth of around 600.
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Affiliation(s)
- M T Manzoni
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, E-08860 Castelldefels (Barcelona), Spain
| | - M Moreno-Cardoner
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, E-08860 Castelldefels (Barcelona), Spain
| | - A Asenjo-Garcia
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, E-08860 Castelldefels (Barcelona), Spain
- Norman Bridge Laboratory of Physics MC12-33, California Institute of Technology, Pasadena, CA 91125, United States of America
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA91125, United States of America
| | - J V Porto
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD 20742, United States of America
| | - A V Gorshkov
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD 20742, United States of America
- Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, MD 20742, United States of America
| | - D E Chang
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, E-08860 Castelldefels (Barcelona), Spain
- ICREA—Institució Catalana de Recerca i Estudis Avançats, E-08015 Barcelona, Spain
- Author to whom any correspondence should be addressed
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23
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24
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Determining phase coherence time of stored light in warm atomic vapor. Sci Rep 2017; 7:15559. [PMID: 29138415 PMCID: PMC5686098 DOI: 10.1038/s41598-017-15469-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 10/23/2017] [Indexed: 11/09/2022] Open
Abstract
In quantum memory based on an atomic medium, we may have a question about whether all information on the stored light is preserved. In particular, the phase coherence between the stored and retrieval light pulses is very interesting, because it can indicate the relationship between the coherence time and storage time of the light. In this paper, we investigate the phase coherence time of light stored in a warm atomic vapor, by examining the beat-note interference between the retrieval light pulse and a reference light beam optically delayed using an optical fiber. The beat-note interference fringes are measured for different reference-light optical delays. The observed retrieval-light phase indicates that the phase of the input probe light is preserved in the medium. However, we further confirm that the retrieval-light phase coherence depends on the phase coherence of the coupling light used for retrieval in the storage process.
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25
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Establishing and storing of deterministic quantum entanglement among three distant atomic ensembles. Nat Commun 2017; 8:718. [PMID: 28959032 PMCID: PMC5620099 DOI: 10.1038/s41467-017-00809-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/28/2017] [Indexed: 11/08/2022] Open
Abstract
It is crucial for the physical realization of quantum information networks to first establish entanglement among multiple space-separated quantum memories and then, at a user-controlled moment, to transfer the stored entanglement to quantum channels for distribution and conveyance of information. Here we present an experimental demonstration on generation, storage, and transfer of deterministic quantum entanglement among three spatially separated atomic ensembles. The off-line prepared multipartite entanglement of optical modes is mapped into three distant atomic ensembles to establish entanglement of atomic spin waves via electromagnetically induced transparency light-matter interaction. Then the stored atomic entanglement is transferred into a tripartite quadrature entangled state of light, which is space-separated and can be dynamically allocated to three quantum channels for conveying quantum information. The existence of entanglement among three released optical modes verifies that the system has the capacity to preserve multipartite entanglement. The presented protocol can be directly extended to larger quantum networks with more nodes.Continuous-variable encoding is a promising approach for quantum information and communication networks. Here, the authors show how to map entanglement from three spatial optical modes to three separated atomic samples via electromagnetically induced transparency, releasing it later on demand.
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26
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Ji L, Gao J, Yang AL, Feng Z, Lin XF, Li ZG, Jin XM. Towards quantum communications in free-space seawater. OPTICS EXPRESS 2017; 25:19795-19806. [PMID: 29041667 DOI: 10.1364/oe.25.019795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/21/2017] [Indexed: 05/27/2023]
Abstract
Long-distance quantum channels capable of transferring quantum states faithfully for unconditionally secure quantum communication have been so far confirmed to be feasible in both fiber and free-space air. However, it remains unclear whether seawater, which covers more than 70% of the earth, can also be utilized, leaving global quantum communication incomplete. Here we experimentally demonstrate that polarization quantum states including general qubits of single photon and entangled states can survive well after travelling through seawater. We perform experiments with seawater collected over a range of 36 kilometers in the Yellow Sea. For single photons at 405 nm in a blue-green window, we obtain an average process fidelity above 98%. For entangled photons at 810nm, albeit very high loss, we observe the violation of Bell inequality with 33 standard deviations. Our results confirm the feasibility of a seawater quantum channel, representing the first step towards underwater quantum communication.
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27
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Kutluer K, Mazzera M, de Riedmatten H. Solid-State Source of Nonclassical Photon Pairs with Embedded Multimode Quantum Memory. PHYSICAL REVIEW LETTERS 2017; 118:210502. [PMID: 28598672 DOI: 10.1103/physrevlett.118.210502] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Indexed: 06/07/2023]
Abstract
The generation and distribution of quantum correlations between photonic qubits is a key resource in quantum information science. For applications in quantum networks and quantum repeaters, it is required that these quantum correlations be stored in a quantum memory. In 2001, Duan, Lukin, Cirac, and Zoller (DLCZ) proposed a scheme combining a correlated photon-pair source and a quantum memory in atomic gases, which has enabled fast progress towards elementary quantum networks. In this Letter, we demonstrate a solid-state source of correlated photon pairs with embedded spin-wave quantum memory, using a rare-earth-ion-doped crystal. We show strong quantum correlations between the photons, high enough for performing quantum communication. Unlike the original DLCZ proposal, our scheme is inherently multimode thanks to a built-in rephasing mechanism, allowing us to demonstrate storage of 11 temporal modes. These results represent an important step towards the realization of complex quantum networks architectures using solid-state resources.
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Affiliation(s)
- Kutlu Kutluer
- ICFO-Institut de Ciencies Fotoniques, the Barcelona Institute of Science and Technology, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Margherita Mazzera
- ICFO-Institut de Ciencies Fotoniques, the Barcelona Institute of Science and Technology, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Hugues de Riedmatten
- ICFO-Institut de Ciencies Fotoniques, the Barcelona Institute of Science and Technology, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain
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28
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Ma L, Slattery O, Tang X. Optical quantum memory based on electromagnetically induced transparency. JOURNAL OF OPTICS (2010) 2017; 19:043001. [PMID: 28828172 PMCID: PMC5562294 DOI: 10.1088/2040-8986/19/4/043001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.
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Affiliation(s)
- Lijun Ma
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899, United States of America
| | - Oliver Slattery
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899, United States of America
| | - Xiao Tang
- Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899, United States of America
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29
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Distante E, Farrera P, Padrón-Brito A, Paredes-Barato D, Heinze G, de Riedmatten H. Storing single photons emitted by a quantum memory on a highly excited Rydberg state. Nat Commun 2017; 8:14072. [PMID: 28102203 PMCID: PMC5253638 DOI: 10.1038/ncomms14072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/18/2016] [Indexed: 11/15/2022] Open
Abstract
Strong interaction between two single photons is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photonic quantum gates and deterministic Bell-state measurements. In the context of quantum networks, it would be important to achieve interactions between single photons from independent photon pairs storable in quantum memories. So far, most experiments showing nonlinearities at the single-photon level have used weak classical input light. Here we demonstrate the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly nonlinear medium based on highly excited Rydberg atoms. We show that nonclassical correlations between the two photons persist after retrieval from the Rydberg ensemble. Our result is an important step towards deterministic photon-photon interactions, and may enable deterministic Bell-state measurements with multimode quantum memories.
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Affiliation(s)
- Emanuele Distante
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
| | - Pau Farrera
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
| | - Auxiliadora Padrón-Brito
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
| | - David Paredes-Barato
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
| | - Georg Heinze
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
| | - Hugues de Riedmatten
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860 Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain
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30
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Facchinetti G, Jenkins SD, Ruostekoski J. Storing Light with Subradiant Correlations in Arrays of Atoms. PHYSICAL REVIEW LETTERS 2016; 117:243601. [PMID: 28009199 DOI: 10.1103/physrevlett.117.243601] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 06/06/2023]
Abstract
We show how strong light-mediated resonant dipole-dipole interactions between atoms can be utilized in a control and storage of light. The method is based on a high-fidelity preparation of a collective atomic excitation in a single correlated subradiant eigenmode in a lattice. We demonstrate how a simple phenomenological model captures the qualitative features of the dynamics and sharp transmission resonances that may find applications in sensing.
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Affiliation(s)
- G Facchinetti
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- École Normale Supérieure de Cachan, 61 avenue du Président Wilson, 94235 Cachan, France
| | - S D Jenkins
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - J Ruostekoski
- Mathematical Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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31
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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.
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32
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Heshami K, England DG, Humphreys PC, Bustard PJ, Acosta VM, Nunn J, Sussman BJ. Quantum memories: emerging applications and recent advances. JOURNAL OF MODERN OPTICS 2016; 63:2005-2028. [PMID: 27695198 PMCID: PMC5020357 DOI: 10.1080/09500340.2016.1148212] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/27/2015] [Indexed: 05/20/2023]
Abstract
Quantum light-matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories.
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Affiliation(s)
| | | | | | | | - Victor M. Acosta
- Department of Physics and Astronomy, University of New Mexico, Center for High Technology Materials, Albuquerque, NM, USA
| | - Joshua Nunn
- Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Benjamin J. Sussman
- National Research Council of Canada, Ottawa, Canada
- Department of Physics, University of Ottawa, Ottawa, Canada
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33
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Bustard PJ, England DG, Heshami K, Kupchak C, Sussman BJ. Reducing noise in a Raman quantum memory. OPTICS LETTERS 2016; 41:5055-5058. [PMID: 27805684 DOI: 10.1364/ol.41.005055] [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
Optical quantum memories are an important component of future optical and hybrid quantum technologies. Raman schemes are strong candidates for use with ultrashort optical pulses due to their broad bandwidth; however, the elimination of deleterious four-wave mixing noise from Raman memories is critical for practical applications. Here, we demonstrate a quantum memory using the rotational states of hydrogen molecules at room temperature. Polarization selection rules prohibit four-wave mixing, allowing the storage and retrieval of attenuated coherent states with a mean photon number 0.9 and a pulse duration 175 fs. The 1/e memory lifetime is 85.5 ps, demonstrating a time-bandwidth product of ≈480 in a memory that is well suited for use with broadband heralded down-conversion and fiber-based photon sources.
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34
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Ding DS, Zhang W, Shi S, Zhou ZY, Li Y, Shi BS, Guo GC. High-dimensional entanglement between distant atomic-ensemble memories. LIGHT, SCIENCE & APPLICATIONS 2016; 5:e16157. [PMID: 30167124 PMCID: PMC6059826 DOI: 10.1038/lsa.2016.157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 05/14/2023]
Abstract
Entangled quantum states in high-dimensional space show many advantages compared with entangled states in two-dimensional space. The former enable quantum communication with higher channel capacity, enable more efficient quantum-information processing and are more feasible for closing the detection loophole in Bell test experiments. Establishing high-dimensional entangled memories is essential for long-distance communication, but its experimental realization is lacking. We experimentally established high-dimensional entanglement in orbital angular momentum space between two atomic ensembles separated by 1 m. We reconstructed the density matrix for a three-dimensional entanglement and obtained an entanglement fidelity of (83.9±2.9)%. More importantly, we confirmed the successful preparation of a state entangled in more than three-dimensional space (up to seven-dimensional) using entanglement witnesses. Achieving high-dimensional entanglement represents a significant step toward a high-capacity quantum network.
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Affiliation(s)
- Dong-Sheng Ding
- Key Laboratory of Quantum Information, 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
| | - Wei Zhang
- Key Laboratory of Quantum Information, 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
| | - Shuai Shi
- Key Laboratory of Quantum Information, 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
| | - Zhi-Yuan Zhou
- Key Laboratory of Quantum Information, 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
| | - Yan Li
- Key Laboratory of Quantum Information, 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
| | - Bao-Sen Shi
- Key Laboratory of Quantum Information, 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, 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
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35
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Coherent and dynamic beam splitting based on light storage in cold atoms. Sci Rep 2016; 6:34279. [PMID: 27677457 PMCID: PMC5039697 DOI: 10.1038/srep34279] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022] Open
Abstract
We demonstrate a coherent and dynamic beam splitter based on light storage in cold atoms. An input weak laser pulse is first stored in a cold atom ensemble via electromagnetically-induced transparency (EIT). A set of counter-propagating control fields, applied at a later time, retrieves the stored pulse into two output spatial modes. The high visibility interference between the two output pulses clearly demonstrates that the beam splitting process is coherent. Furthermore, by manipulating the control lasers, it is possible to dynamically control the storage time, the power splitting ratio, the relative phase, and the optical frequencies of the output pulses. With further improvements, the active beam splitter demonstrated in this work might have applications in photonic photonic quantum information and in all-optical information processing.
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36
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Abstract
Einstein was wrong with his 1927 Solvay Conference claim that quantum mechanics is incomplete and incapable of describing diffraction of single particles. However, the Einstein-Podolsky-Rosen paradox of entangled pairs of particles remains lurking with its 'spooky action at a distance'. In molecules quantum entanglement can be viewed as basis of both chemical bonding and excitonic states. The latter are important in many biophysical contexts and involve coupling between subsystems in which virtual excitations lead to eigenstates of the total Hamiltonian, but not for the separate subsystems. The author questions whether atomic or photonic systems may be probed to prove that particles or photons may stay entangled over large distances and display the immediate communication with each other that so concerned Einstein. A dissociating hydrogen molecule is taken as a model of a zero-spin entangled system whose angular momenta are in principle possible to probe for this purpose. In practice, however, spins randomize as a result of interactions with surrounding fields and matter. Similarly, no experiment seems yet to provide unambiguous evidence of remaining entanglement between single photons at large separations in absence of mutual interaction, or about immediate (superluminal) communication. This forces us to reflect again on what Einstein really had in mind with the paradox, viz. a probabilistic interpretation of a wave function for an ensemble of identically prepared states, rather than as a statement about single particles. Such a prepared state of many particles would lack properties of quantum entanglement that make it so special, including the uncertainty upon which safe quantum communication is assumed to rest. An example is Zewail's experiment showing visible resonance in the dissociation of a coherently vibrating ensemble of NaI molecules apparently violating the uncertainty principle. Einstein was wrong about diffracting single photons where space-like anti-bunching observations have proven recently their non-local character and how observation in one point can remotely affect the outcome in other points. By contrast, long range photon entanglement with immediate, superluminal response is still an elusive, possibly partly misunderstood issue. The author proposes that photons may entangle over large distances only if some interaction exists via fields that cannot propagate faster than the speed of light. An experiment to settle this 'interaction hypothesis' is suggested.
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37
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Deterministically Entangling Two Remote Atomic Ensembles via Light-Atom Mixed Entanglement Swapping. Sci Rep 2016; 6:25715. [PMID: 27165122 PMCID: PMC4863164 DOI: 10.1038/srep25715] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 04/21/2016] [Indexed: 11/21/2022] Open
Abstract
Entanglement of two distant macroscopic objects is a key element for implementing large-scale quantum networks consisting of quantum channels and quantum nodes. Entanglement swapping can entangle two spatially separated quantum systems without direct interaction. Here we propose a scheme of deterministically entangling two remote atomic ensembles via continuous-variable entanglement swapping between two independent quantum systems involving light and atoms. Each of two stationary atomic ensembles placed at two remote nodes in a quantum network is prepared to a mixed entangled state of light and atoms respectively. Then, the entanglement swapping is unconditionally implemented between the two prepared quantum systems by means of the balanced homodyne detection of light and the feedback of the measured results. Finally, the established entanglement between two macroscopic atomic ensembles is verified by the inseparability criterion of correlation variances between two anti-Stokes optical beams respectively coming from the two atomic ensembles.
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38
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Tiarks D, Schmidt S, Rempe G, Dürr S. Optical π phase shift created with a single-photon pulse. SCIENCE ADVANCES 2016; 2:e1600036. [PMID: 27386511 PMCID: PMC4928902 DOI: 10.1126/sciadv.1600036] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/30/2016] [Indexed: 05/15/2023]
Abstract
A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.
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39
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Trotta R, Martín-Sánchez J, Wildmann JS, Piredda G, Reindl M, Schimpf C, Zallo E, Stroj S, Edlinger J, Rastelli A. Wavelength-tunable sources of entangled photons interfaced with atomic vapours. Nat Commun 2016; 7:10375. [PMID: 26815609 PMCID: PMC4737804 DOI: 10.1038/ncomms10375] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/03/2015] [Indexed: 12/03/2022] Open
Abstract
The prospect of using the quantum nature of light for secure communication keeps spurring the search and investigation of suitable sources of entangled photons. A single semiconductor quantum dot is one of the most attractive, as it can generate indistinguishable entangled photons deterministically and is compatible with current photonic-integration technologies. However, the lack of control over the energy of the entangled photons is hampering the exploitation of dissimilar quantum dots in protocols requiring the teleportation of quantum entanglement over remote locations. Here we introduce quantum dot-based sources of polarization-entangled photons whose energy can be tuned via three-directional strain engineering without degrading the degree of entanglement of the photon pairs. As a test-bench for quantum communication, we interface quantum dots with clouds of atomic vapours, and we demonstrate slow-entangled photons from a single quantum emitter. These results pave the way towards the implementation of hybrid quantum networks where entanglement is distributed among distant parties using optoelectronic devices.
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Affiliation(s)
- Rinaldo Trotta
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
| | - Javier Martín-Sánchez
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
| | - Johannes S. Wildmann
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
| | - Giovanni Piredda
- Forschungszentrum Mikrotechnik, FH Vorarlberg, Hochschulstr. 1, A-6850 Dornbirn, Austria
| | - Marcus Reindl
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
| | - Christian Schimpf
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
| | - Eugenio Zallo
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteilplatz 5-7, 10117 Berlin, Germany
| | - Sandra Stroj
- Forschungszentrum Mikrotechnik, FH Vorarlberg, Hochschulstr. 1, A-6850 Dornbirn, Austria
| | - Johannes Edlinger
- Forschungszentrum Mikrotechnik, FH Vorarlberg, Hochschulstr. 1, A-6850 Dornbirn, Austria
| | - Armando Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria
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40
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Costanzo LS, Coelho AS, Pellegrino D, Mendes MS, Acioli L, Cassemiro KN, Felinto D, Zavatta A, Bellini M. Zero-Area Single-Photon Pulses. PHYSICAL REVIEW LETTERS 2016; 116:023602. [PMID: 26824539 DOI: 10.1103/physrevlett.116.023602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Indexed: 06/05/2023]
Abstract
Broadband single photons are usually considered not to couple efficiently to atomic gases because of the large mismatch in bandwidth. Contrary to this intuitive picture, here we demonstrate that the interaction of ultrashort single photons with a dense resonant atomic sample deeply modifies the temporal shape of their wave packet mode without degrading their nonclassical character, and effectively generates zero-area single-photon pulses. This is a clear signature of strong transient coupling between single broadband (THz-level) light quanta and atoms, with intriguing fundamental implications and possible new applications to the storage of quantum information.
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Affiliation(s)
- L S Costanzo
- Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Florence, Italy
- European Laboratory for Non-linear Spectroscopy (LENS) and Department of Physics, University of Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - A S Coelho
- Departamento de Engenharia, Centro Universitário UNINOFAPI, 64073-505 Teresina, Piauí, Brazil
| | - D Pellegrino
- European Laboratory for Non-linear Spectroscopy (LENS) and Department of Physics, University of Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - M S Mendes
- Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil
| | - L Acioli
- Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil
| | - K N Cassemiro
- Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil
| | - D Felinto
- Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil
| | - A Zavatta
- Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Florence, Italy
- European Laboratory for Non-linear Spectroscopy (LENS) and Department of Physics, University of Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - M Bellini
- Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Florence, Italy
- European Laboratory for Non-linear Spectroscopy (LENS) and Department of Physics, University of Firenze, 50019 Sesto Fiorentino, Florence, Italy
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41
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Abstract
Coherent storage of optical image in a coherently-driven medium is a promising method with possible applications in many fields. In this work, we experimentally report a controllable spatial-frequency routing of image via atomic spin coherence in a solid-state medium driven by electromagnetically induced transparency (EIT). Under the EIT-based light-storage regime, a transverse spatial image carried by the probe field is stored into atomic spin coherence. By manipulating the frequency and spatial propagation direction of the read control field, the stored image is transferred into a new spatial-frequency channel. When two read control fields are used to retrieve the stored information, the image information is converted into a superposition of two spatial-frequency modes. Through this technique, the image is manipulated coherently and all-optically in a controlled fashion.
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42
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Albrecht B, Farrera P, Heinze G, Cristiani M, de Riedmatten H. Controlled Rephasing of Single Collective Spin Excitations in a Cold Atomic Quantum Memory. PHYSICAL REVIEW LETTERS 2015; 115:160501. [PMID: 26550854 DOI: 10.1103/physrevlett.115.160501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate active control of inhomogeneous dephasing and rephasing for single collective atomic spin excitations (spin waves) created by spontaneous Raman scattering in a quantum memory based on cold 87Rb atoms. The control is provided by a reversible external magnetic field gradient inducing an inhomogeneous broadening of the atomic hyperfine levels. We demonstrate experimentally that active rephasing preserves the single photon nature of the retrieved photons. Finally, we show that the control of the inhomogeneous dephasing enables the creation of time-separated spin waves in a single ensemble followed by a selective read-out in time. This is an important step towards the implementation of a functional temporally multiplexed quantum repeater node.
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Affiliation(s)
- Boris Albrecht
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Pau Farrera
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Georg Heinze
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Matteo Cristiani
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - Hugues de Riedmatten
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain
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43
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Monteiro F, Caprara Vivoli V, Guerreiro T, Martin A, Bancal JD, Zbinden H, Thew RT, Sangouard N. Revealing genuine optical-path entanglement. PHYSICAL REVIEW LETTERS 2015; 114:170504. [PMID: 25978215 DOI: 10.1103/physrevlett.114.170504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Indexed: 06/04/2023]
Abstract
How can one detect entanglement between multiple optical paths sharing a single photon? We address this question by proposing a scalable protocol, which only uses local measurements where single photon detection is combined with small displacement operations. The resulting entanglement witness does not require postselection, nor assumptions about the photon number in each path. Furthermore, it guarantees that entanglement lies in a subspace with at most one photon per optical path and reveals genuinely multipartite entanglement. We demonstrate its scalability and resistance to loss by performing various experiments with two and three optical paths. We anticipate applications of our results for quantum network certification.
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Affiliation(s)
- F Monteiro
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - V Caprara Vivoli
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - T Guerreiro
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - A Martin
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - J-D Bancal
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
| | - H Zbinden
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - R T Thew
- Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - N Sangouard
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
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44
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Jang S, Hwang E, Lee Y, Lee S, Cho JH. Multifunctional graphene optoelectronic devices capable of detecting and storing photonic signals. NANO LETTERS 2015; 15:2542-2547. [PMID: 25811444 DOI: 10.1021/acs.nanolett.5b00105] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The advantages of graphene photodetectors were utilized to design a new multifunctional graphene optoelectronic device. Organic semiconductors, gold nanoparticles (AuNPs), and graphene were combined to fabricate a photodetecting device with a nonvolatile memory function for storing photonic signals. A pentacene organic semiconductor acted as a light absorption layer in the device and provided a high hole photocurrent to the graphene channel. The AuNPs, positioned between the tunneling and blocking dielectric layers, acted as both a charge trap layer and a plasmonic light scatterer, which enable storing of the information about the incident light. The proposed pentacene-graphene-AuNP hybrid photodetector not only performed well as a photodetector in the visible light range, it also was able to store the photonic signal in the form of persistent current. The good photodetection performance resulted from the plasmonics-enabled enhancement of the optical absorption and from the photogating mechanisms in the pentacene. The device provided a photoresponse that depended on the wavelength of incident light; therefore, the signal information (both the wavelength and intensity) of the incident light was effectively committed to memory. The simple process of applying a negative pulse gate voltage could then erase the programmed information. The proposed photodetector with the capacity to store a photonic signal in memory represents a significant step toward the use of graphene in optoelectronic devices.
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Affiliation(s)
- Sukjae Jang
- †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Euyheon Hwang
- †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Youngbin Lee
- †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Seungwoo Lee
- †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Jeong Ho Cho
- †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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45
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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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46
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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: 10.1103/physrevlett.114.050502] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 05/09/2023]
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.
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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
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47
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England DG, Fisher KAG, MacLean JPW, Bustard PJ, Lausten R, Resch KJ, Sussman BJ. Storage and retrieval of THz-bandwidth single photons using a room-temperature diamond quantum memory. PHYSICAL REVIEW LETTERS 2015; 114:053602. [PMID: 25699439 DOI: 10.1103/physrevlett.114.053602] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Indexed: 06/04/2023]
Abstract
We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of a room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric down-conversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is g((2))(0)=0.65±0.07, demonstrating a preservation of nonclassical photon statistics throughout storage and retrieval. The memory is low noise, high speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications.
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Affiliation(s)
- Duncan G England
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Kent A G Fisher
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Jean-Philippe W MacLean
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Philip J Bustard
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Rune Lausten
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Kevin J Resch
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Benjamin J Sussman
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
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48
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Quantum Light Storage in Solid State Atomic Ensembles. ENGINEERING THE ATOM-PHOTON INTERACTION 2015. [DOI: 10.1007/978-3-319-19231-4_9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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49
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Lee MJ, Ruseckas J, Lee CY, Kudriašov V, Chang KF, Cho HW, Juzeliānas G, Yu IA. Experimental demonstration of spinor slow light. Nat Commun 2014; 5:5542. [PMID: 25417851 PMCID: PMC4263133 DOI: 10.1038/ncomms6542] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/10/2014] [Indexed: 11/09/2022] Open
Abstract
Slow light based on the effect of electromagnetically induced transparency is of great interest due to its applications in low-light-level nonlinear optics and quantum information manipulation. The previous experiments all dealt with the single-component slow light. Here, we report the experimental demonstration of two-component or spinor slow light using a double-tripod atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by six light fields. The oscillation due to the interaction between the two components was observed. On the basis of the stored light, our data showed that the double-tripod scheme behaves like the two outcomes of an interferometer enabling precision measurements of frequency detuning. We experimentally demonstrated a possible application of the double-tripod scheme as quantum memory/rotator for the two-colour qubit. Our study also suggests that the spinor slow light is a better method than a widely used scheme in the nonlinear frequency conversion.
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Affiliation(s)
- Meng-Jung Lee
- Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Julius Ruseckas
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania
| | - Chin-Yuan Lee
- Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Viačeslav Kudriašov
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania
| | - Kao-Fang Chang
- Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Hung-Wen Cho
- Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Gediminas Juzeliānas
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, Vilnius 01108, Lithuania
| | - Ite A Yu
- Department of Physics and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
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Yang X, Xue B, Zhang J, Zhu S. A universal quantum information processor for scalable quantum communication and networks. Sci Rep 2014; 4:6629. [PMID: 25316514 PMCID: PMC4197420 DOI: 10.1038/srep06629] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/29/2014] [Indexed: 11/15/2022] Open
Abstract
Entanglement provides an essential resource for quantum computation, quantum communication, and quantum networks. How to conveniently and efficiently realize the generation, distribution, storage, retrieval, and control of multipartite entanglement is the basic requirement for realistic quantum information processing. Here, we present a theoretical proposal to efficiently and conveniently achieve a universal quantum information processor (QIP) via atomic coherence in an atomic ensemble. The atomic coherence, produced through electromagnetically induced transparency (EIT) in the Λ-type configuration, acts as the QIP and has full functions of quantum beam splitter, quantum frequency converter, quantum entangler, and quantum repeater. By employing EIT-based nondegenerate four-wave mixing processes, the generation, exchange, distribution, and manipulation of light-light, atom-light, and atom-atom multipartite entanglement can be efficiently and flexibly achieved in a deterministic way with only coherent light fields. This method greatly facilitates the operations in quantum information processing, and holds promising applications in realistic scalable quantum communication and quantum networks.
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Affiliation(s)
- Xihua Yang
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Bolin Xue
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Junxiang Zhang
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China
| | - Shiyao Zhu
- Beijing Computational Science Research Center, Beijing 100084, China
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