1
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Liu JL, Luo XY, Yu Y, Wang CY, Wang B, Hu Y, Li J, Zheng MY, Yao B, Yan Z, Teng D, Jiang JW, Liu XB, Xie XP, Zhang J, Mao QH, Jiang X, Zhang Q, Bao XH, Pan JW. Creation of memory-memory entanglement in a metropolitan quantum network. Nature 2024; 629:579-585. [PMID: 38750235 DOI: 10.1038/s41586-024-07308-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 03/13/2024] [Indexed: 05/18/2024]
Abstract
Towards realizing the future quantum internet1,2, a pivotal milestone entails the transition from two-node proof-of-principle experiments conducted in laboratories to comprehensive multi-node set-ups on large scales. Here we report the creation of memory-memory entanglement in a multi-node quantum network over a metropolitan area. We use three independent memory nodes, each of which is equipped with an atomic ensemble quantum memory3 that has telecom conversion, together with a photonic server where detection of a single photon heralds the success of entanglement generation. The memory nodes are maximally separated apart for 12.5 kilometres. We actively stabilize the phase variance owing to fibre links and control lasers. We demonstrate concurrent entanglement generation between any two memory nodes. The memory lifetime is longer than the round-trip communication time. Our work provides a metropolitan-scale testbed for the evaluation and exploration of multi-node quantum network protocols and starts a stage of quantum internet research.
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Affiliation(s)
- Jian-Long Liu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Xi-Yu Luo
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Yong Yu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Chao-Yang Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Bin Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Yi Hu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Jun Li
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | | | - Bo Yao
- Anhui Provincial Key Laboratory of Photonics Devices and Materials, Anhui Institute of Optical and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei, China
- Advanced Laser Technology Laboratory of Anhui Province, Hefei, China
| | - Zi Yan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Da Teng
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Jin-Wei Jiang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Xiao-Bing Liu
- Anhui Provincial Key Laboratory of Photonics Devices and Materials, Anhui Institute of Optical and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei, China
- Advanced Laser Technology Laboratory of Anhui Province, Hefei, China
| | - Xiu-Ping Xie
- Jinan Institute of Quantum Technology, Jinan, China
| | - Jun Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Qing-He Mao
- Anhui Provincial Key Laboratory of Photonics Devices and Materials, Anhui Institute of Optical and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei, China
- Advanced Laser Technology Laboratory of Anhui Province, Hefei, China
- School of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, China
| | - Xiao Jiang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
| | - Qiang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China
- Jinan Institute of Quantum Technology, Jinan, China
| | - Xiao-Hui Bao
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China.
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
| | - Jian-Wei Pan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China.
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
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2
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Fang RZ, Lai XY, Li T, Su RZ, Lu BW, Yang CW, Liu RZ, Qiao YK, Li C, He ZG, Huang J, Li H, You LX, Huo YH, Bao XH, Pan JW. Experimental Generation of Spin-Photon Entanglement in Silicon Carbide. PHYSICAL REVIEW LETTERS 2024; 132:160801. [PMID: 38701444 DOI: 10.1103/physrevlett.132.160801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/20/2024] [Indexed: 05/05/2024]
Abstract
A solid-state approach for quantum networks is advantageous, as it allows the integration of nanophotonics to enhance the photon emission and the utilization of weakly coupled nuclear spins for long-lived storage. Silicon carbide, specifically point defects within it, shows great promise in this regard due to the easy of availability and well-established nanofabrication techniques. Despite of remarkable progresses made, achieving spin-photon entanglement remains a crucial aspect to be realized. In this Letter, we experimentally generate entanglement between a silicon vacancy defect in silicon carbide and a scattered single photon in the zero-phonon line. The spin state is measured by detecting photons scattered in the phonon sideband. The photonic qubit is encoded in the time-bin degree of freedom and measured using an unbalanced Mach-Zehnder interferometer. Photonic correlations not only reveal the quality of the entanglement but also verify the deterministic nature of the entanglement creation process. By harnessing two pairs of such spin-photon entanglement, it becomes straightforward to entangle remote quantum nodes at long distance.
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Affiliation(s)
- Ren-Zhou Fang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Xiao-Yi Lai
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Tao Li
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Ren-Zhu Su
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Bo-Wei Lu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Chao-Wei Yang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Run-Ze Liu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Yu-Kun Qiao
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Cheng Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Zhi-Gang He
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Jia Huang
- State Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China
| | - Hao Li
- State Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China
| | - Li-Xing You
- State Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China
| | - Yong-Heng Huo
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Xiao-Hui Bao
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Jian-Wei Pan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
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3
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Guo Y, Ji W, Kong X, Wang M, Sun H, Zhou J, Chai Z, Rong X, Shi F, Wang Y, Du J. Single-Shot Readout of a Solid-State Electron Spin Qutrit. PHYSICAL REVIEW LETTERS 2024; 132:060601. [PMID: 38394571 DOI: 10.1103/physrevlett.132.060601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 01/09/2024] [Indexed: 02/25/2024]
Abstract
Quantum systems usually feature a rich multilevel structure with promising resources for developing superior quantum technologies compared with their binary counterpart. Single-shot readout of these high-dimensional quantum systems is essential for exploiting their potential. Although there have been various high-spin systems, the single-shot readout of the overall state of high-spin systems remains a challenging issue. Here we demonstrate a reliable single-shot readout of spin qutrit state in a low-temperature solid-state system utilizing a binary readout scheme. We achieve a single-shot readout of an electron spin qutrit associated with a single nitrogen-vacancy center in diamond with an average fidelity of 87.80%. We use this spin qutrit system to verify quantum contextuality, a fundamental test of quantum mechanics. We observe a violation of the noncontextual hidden variable inequality with the developed single-shot readout in contrast to the conventional binary readout. These results pave the way for developing quantum information processing based on spin qutrits.
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Affiliation(s)
- Yuhang Guo
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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
| | - Wentao Ji
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Xi Kong
- The State Key Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - Mengqi Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Haoyu Sun
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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
| | - Jingyang Zhou
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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
| | - Zihua Chai
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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
| | - Xing Rong
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Fazhan Shi
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Ya Wang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Jiangfeng Du
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
- School of Physics, Zhejiang University, Hangzhou 310027, China
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4
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Murakami S, Fujimoto R, Kobayashi T, Ikuta R, Inoue A, Umeki T, Miki S, China F, Terai H, Kasahara R, Mukai T, Imoto N, Yamamoto T. Quantum frequency conversion using 4-port fiber-pigtailed PPLN module. OPTICS EXPRESS 2023; 31:29271-29279. [PMID: 37710731 DOI: 10.1364/oe.494313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/07/2023] [Indexed: 09/16/2023]
Abstract
Quantum frequency conversion (QFC), which involves the exchange of frequency modes of photons, is a prerequisite for quantum interconnects among various quantum systems, primarily those based on telecom photonic network infrastructures. Compact and fiber-closed QFC modules are in high demand for such applications. In this paper, we report such a QFC module based on a fiber-coupled 4-port frequency converter with a periodically poled lithium niobate (PPLN) waveguide. The demonstrated QFC shifted the wavelength of a single photon from 780 to 1541 nm. The single photon was prepared via spontaneous parametric down-conversion (SPDC) with heralding photon detection, for which the cross-correlation function was 40.45 ± 0.09. The observed cross-correlation function of the photon pairs had a nonclassical value of 13.7 ± 0.4 after QFC at the maximum device efficiency of 0.73, which preserved the quantum statistical property. Such an efficient QFC module is useful for interfacing atomic systems and fiber-optic communication.
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5
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Logan AD, Shree S, Chakravarthi S, Yama N, Pederson C, Hestroffer K, Hatami F, Fu KMC. Triply-resonant sum frequency conversion with gallium phosphide ring resonators. OPTICS EXPRESS 2023; 31:1516-1531. [PMID: 36785185 DOI: 10.1364/oe.473211] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/13/2022] [Indexed: 06/18/2023]
Abstract
We demonstrate quasi-phase matched, triply-resonant sum frequency conversion in 10.6-µm-diameter integrated gallium phosphide ring resonators. A small-signal, waveguide-to-waveguide power conversion efficiency of 8 ± 1.1%/mW; is measured for conversion from telecom (1536 nm) and near infrared (1117 nm) to visible (647 nm) wavelengths with an absolute power conversion efficiency of 6.3 ± 0.6%; measured at saturation pump power. For the complementary difference frequency generation process, a single photon conversion efficiency of 7.2%/mW from visible to telecom is projected for resonators with optimized coupling. Efficient conversion from visible to telecom will facilitate long-distance transmission of spin-entangled photons from solid-state emitters such as the diamond NV center, allowing long-distance entanglement for quantum networks.
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6
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Laorenza DW, Freedman DE. Could the Quantum Internet Be Comprised of Molecular Spins with Tunable Optical Interfaces? J Am Chem Soc 2022; 144:21810-21825. [DOI: 10.1021/jacs.2c07775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Daniel W. Laorenza
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Danna E. Freedman
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
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7
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Liu DC, Li PY, Zhu TX, Zheng L, Huang JY, Zhou ZQ, Li CF, Guo GC. On-Demand Storage of Photonic Qubits at Telecom Wavelengths. PHYSICAL REVIEW LETTERS 2022; 129:210501. [PMID: 36461974 DOI: 10.1103/physrevlett.129.210501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Quantum memories at telecom wavelengths are crucial for the construction of large-scale quantum networks based on existing fiber networks. On-demand storage of telecom photonic qubits is an essential request for such networking applications but yet to be demonstrated. Here we demonstrate the storage and on-demand retrieval of telecom photonic qubits using a laser-written waveguide fabricated in an ^{167}Er^{3+}:Y_{2}SiO_{5} crystal. Both ends of the waveguide memory are directly connected with fiber arrays with a fiber-to-fiber efficiency of 51%. Storage fidelity of 98.3(1)% can be obtained for time-bin qubits encoded with single-photon-level coherent pulses, which is far beyond the maximal fidelity that can be achieved with a classical measure and prepared strategy. This device features high reliability and easy scalability, and it can be directly integrated into fiber networks, which could play an essential role in fiber-based quantum networks.
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Affiliation(s)
- Duan-Cheng Liu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Pei-Yun Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Tian-Xiang Zhu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Liang Zheng
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Jian-Yin Huang
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Zong-Quan Zhou
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Chuan-Feng Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Guang-Can Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China and Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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8
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Luo XY, Yu Y, Liu JL, Zheng MY, Wang CY, Wang B, Li J, Jiang X, Xie XP, Zhang Q, Bao XH, Pan JW. Postselected Entanglement between Two Atomic Ensembles Separated by 12.5 km. PHYSICAL REVIEW LETTERS 2022; 129:050503. [PMID: 35960556 DOI: 10.1103/physrevlett.129.050503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Quantum internet gives the promise of getting all quantum resources connected, and it will enable applications far beyond a localized scenario. A prototype is a network of quantum memories that are entangled and well separated. In this Letter, we report the establishment of postselected entanglement between two atomic quantum memories physically separated by 12.5 km directly. We create atom-photon entanglement in one node and send the photon to a second node for storage via electromagnetically induced transparency. We harness low-loss transmission through a field-deployed fiber of 20.5 km by making use of frequency down-conversion and up-conversion. The final memory-memory entanglement is verified to have a fidelity of 90% via retrieving to photons. Our experiment makes a significant step forward toward the realization of a practical metropolitan-scale quantum network.
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Affiliation(s)
- Xi-Yu Luo
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Yong Yu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Jian-Long Liu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | | | - Chao-Yang Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Bin Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Jun Li
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Xiao Jiang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Xiu-Ping Xie
- Jinan Institute of Quantum Technology, Jinan 250101, China
| | - Qiang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
- Jinan Institute of Quantum Technology, Jinan 250101, China
| | - Xiao-Hui Bao
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
| | - Jian-Wei Pan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, 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, University of Science and Technology of China, Hefei 230088, China
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9
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van Leent T, Bock M, Fertig F, Garthoff R, Eppelt S, Zhou Y, Malik P, Seubert M, Bauer T, Rosenfeld W, Zhang W, Becher C, Weinfurter H. Entangling single atoms over 33 km telecom fibre. Nature 2022; 607:69-73. [PMID: 35794269 PMCID: PMC9259499 DOI: 10.1038/s41586-022-04764-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 04/14/2022] [Indexed: 11/09/2022]
Abstract
Quantum networks promise to provide the infrastructure for many disruptive applications, such as efficient long-distance quantum communication and distributed quantum computing1,2. Central to these networks is the ability to distribute entanglement between distant nodes using photonic channels. Initially developed for quantum teleportation3,4 and loophole-free tests of Bell's inequality5,6, recently, entanglement distribution has also been achieved over telecom fibres and analysed retrospectively7,8. Yet, to fully use entanglement over long-distance quantum network links it is mandatory to know it is available at the nodes before the entangled state decays. Here we demonstrate heralded entanglement between two independently trapped single rubidium atoms generated over fibre links with a length up to 33 km. For this, we generate atom-photon entanglement in two nodes located in buildings 400 m line-of-sight apart and to overcome high-attenuation losses in the fibres convert the photons to telecom wavelength using polarization-preserving quantum frequency conversion9. The long fibres guide the photons to a Bell-state measurement setup in which a successful photonic projection measurement heralds the entanglement of the atoms10. Our results show the feasibility of entanglement distribution over telecom fibre links useful, for example, for device-independent quantum key distribution11-13 and quantum repeater protocols. The presented work represents an important step towards the realization of large-scale quantum network links.
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Affiliation(s)
- Tim van Leent
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Matthias Bock
- Department of Physics, Saarland University, Saarbrücken, Germany
- Institute of Experimental Physics, University of Innsbruck, Innsbruck, Austria
| | - Florian Fertig
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Robert Garthoff
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Sebastian Eppelt
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Yiru Zhou
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Pooja Malik
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Matthias Seubert
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Tobias Bauer
- Department of Physics, Saarland University, Saarbrücken, Germany
| | - Wenjamin Rosenfeld
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Center for Quantum Science and Technology, Munich, Germany
| | - Wei Zhang
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany.
- Munich Center for Quantum Science and Technology, Munich, Germany.
- School of Physics, Xi'An Jiao Tong University, Xi'An, ShannXi, China.
| | - Christoph Becher
- Department of Physics, Saarland University, Saarbrücken, Germany.
| | - Harald Weinfurter
- Faculty of Physics, Ludwig-Maximilians-University of Munich, Munich, Germany.
- Munich Center for Quantum Science and Technology, Munich, Germany.
- Max-Planck Institute for Quantum Optics, Garching, Germany.
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10
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Frequency Conversion Interface towards Quantum Network: From Atomic Transition Line to Fiber Optical Communication Band. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12136522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Quantum repeater is a key component of quantum network, and atomic memory is one of the important candidates for constructing quantum repeater. However, the atomic transition wavelength is not suitable for long-distance transmission in optical fiber. To bridge atomic memory and fiber communication, we demonstrate a frequency conversion interface from rubidium D1 line (795 nm) to the optical communication L-band (1621 nm) based on difference frequency generation. To reduce broadband noise of spontaneous Raman scattering caused by strong pumping light, we use a combination of two cascaded etalons and a Fabry-Perot cavity with low finesse to narrow the noise bandwidth to 11.7 MHz. The filtering system is built by common optical elements and is easy to use; it can be widely applied in frequency conversion process. We show that the signal-noise ratio of the converted field is good enough to reduce the input photon number below 1 under the condition of low external device conversion efficiency (0.51%) and large duration of input pulse (250 ns). The demonstrated frequency conversion interface has important potential application in quantum networks.
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11
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Appel MH, Tiranov A, Pabst S, Chan ML, Starup C, Wang Y, Midolo L, Tiurev K, Scholz S, Wieck AD, Ludwig A, Sørensen AS, Lodahl P. Entangling a Hole Spin with a Time-Bin Photon: A Waveguide Approach for Quantum Dot Sources of Multiphoton Entanglement. PHYSICAL REVIEW LETTERS 2022; 128:233602. [PMID: 35749189 DOI: 10.1103/physrevlett.128.233602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/13/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Deterministic sources of multiphoton entanglement are highly attractive for quantum information processing but are challenging to realize experimentally. In this Letter, we demonstrate a route toward a scaleable source of time-bin encoded Greenberger-Horne-Zeilinger and linear cluster states from a solid-state quantum dot embedded in a nanophotonic crystal waveguide. By utilizing a self-stabilizing double-pass interferometer, we measure a spin-photon Bell state with (67.8±0.4)% fidelity and devise steps for significant further improvements. By employing strict resonant excitation, we demonstrate a photon indistinguishability of (95.7±0.8)%, which is conducive to fusion of multiple cluster states for scaling up the technology and producing more general graph states.
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Affiliation(s)
- Martin Hayhurst Appel
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Alexey Tiranov
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Simon Pabst
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Ming Lai Chan
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Christian Starup
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Ying Wang
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Leonardo Midolo
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Konstantin Tiurev
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Sven Scholz
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Anders Søndberg Sørensen
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
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12
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Rakonjac JV, Lago-Rivera D, Seri A, Mazzera M, Grandi S, de Riedmatten H. Entanglement between a Telecom Photon and an On-Demand Multimode Solid-State Quantum Memory. PHYSICAL REVIEW LETTERS 2021; 127:210502. [PMID: 34860116 DOI: 10.1103/physrevlett.127.210502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Entanglement between photons at telecommunication wavelengths and long-lived quantum memories is one of the fundamental requirements of long-distance quantum communication. Quantum memories featuring on-demand readout and multimode operation are additional precious assets that will benefit the communication rate. In this Letter, we report the first demonstration of entanglement between a telecom photon and a collective spin excitation in a multimode solid-state quantum memory. Photon pairs are generated through widely nondegenerate parametric down-conversion, featuring energy-time entanglement between the telecom-wavelength idler and a visible signal photon. The latter is stored in a Pr^{3+}:Y_{2}SiO_{5} crystal as a spin wave using the full atomic frequency comb scheme. We then recall the stored signal photon and analyze the entanglement using the Franson scheme. We measure conditional fidelities of 92(2)% for excited-state storage, enough to violate a Clauser-Horne-Shimony-Holt inequality, and 77(2)% for spin-wave storage. Taking advantage of the on-demand readout from the spin state, we extend the entanglement storage in the quantum memory for up to 47.7 μs, which could allow for the distribution of entanglement between quantum nodes separated by distances of up to 10 km.
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Affiliation(s)
- Jelena V Rakonjac
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Dario Lago-Rivera
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Alessandro Seri
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Margherita Mazzera
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Samuele Grandi
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Hugues de Riedmatten
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain
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13
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Lee JH, Jeon WB, Moon JS, Lee J, Han SW, Bodrog Z, Gali A, Lee SY, Kim JH. Strong Zero-Phonon Transition from Point Defect-Stacking Fault Complexes in Silicon Carbide Nanowires. NANO LETTERS 2021; 21:9187-9194. [PMID: 34677068 DOI: 10.1021/acs.nanolett.1c03013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Crystallographic defects such as vacancies and stacking faults engineer electronic band structure at the atomic level and create zero- and two-dimensional quantum structures in crystals. The combination of these point and planar defects can generate a new type of defect complex system. Here, we investigate silicon carbide nanowires that host point defects near stacking faults. These point-planar defect complexes in the nanowire exhibit outstanding optical properties of high-brightness single photons (>360 kcounts/s), a fast recombination time (<1 ns), and a high Debye-Waller factor (>50%). These distinct optical properties of coupled point-planar defects lead to an unusually strong zero-phonon transition, essential for achieving highly efficient quantum interactions between multiple qubits. Our findings can be extended to other defects in various materials and therefore offer a new perspective for engineering defect qubits.
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Affiliation(s)
- Jin Hee Lee
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Woong Bae Jeon
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Jong Sung Moon
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Junghyun Lee
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Sang-Wook Han
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Zoltán Bodrog
- Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, Hungary
| | - Adam Gali
- Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, Hungary
- Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8., H-1111 Budapest, Hungary
| | - Sang-Yun Lee
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Je-Hyung Kim
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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14
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Lachman L, Filip R. Quantum Non-Gaussian Photon Coincidences. PHYSICAL REVIEW LETTERS 2021; 126:213604. [PMID: 34114867 DOI: 10.1103/physrevlett.126.213604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/21/2021] [Indexed: 06/12/2023]
Abstract
Photon coincidences represent an important resource for quantum technologies. They expose nonlinear quantum processes in matter and are essential for sources of entanglement. We derive broadly applicable criteria for quantum non-Gaussian two-photon coincidences that certify a new quality of photon sources. The criteria reject states emerging from Gaussian parametric processes, which often limit applications in quantum technologies. We also analyze the robustness of the quantum non-Gaussian coincidences and compare it to the heralded quantum non-Gaussianity of single photons based on them.
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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
| | - Radim Filip
- Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
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15
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Pompili M, Hermans SLN, Baier S, Beukers HKC, Humphreys PC, Schouten RN, Vermeulen RFL, Tiggelman MJ, Dos Santos Martins L, Dirkse B, Wehner S, Hanson R. Realization of a multinode quantum network of remote solid-state qubits. Science 2021; 372:259-264. [PMID: 33859028 DOI: 10.1126/science.abg1919] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/19/2021] [Indexed: 11/02/2022]
Abstract
The distribution of entangled states across the nodes of a future quantum internet will unlock fundamentally new technologies. Here, we report on the realization of a three-node entanglement-based quantum network. We combine remote quantum nodes based on diamond communication qubits into a scalable phase-stabilized architecture, supplemented with a robust memory qubit and local quantum logic. In addition, we achieve real-time communication and feed-forward gate operations across the network. We demonstrate two quantum network protocols without postselection: the distribution of genuine multipartite entangled states across the three nodes and entanglement swapping through an intermediary node. Our work establishes a key platform for exploring, testing, and developing multinode quantum network protocols and a quantum network control stack.
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Affiliation(s)
- M Pompili
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - S L N Hermans
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - S Baier
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - H K C Beukers
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - P C Humphreys
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - R N Schouten
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - R F L Vermeulen
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - M J Tiggelman
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - L Dos Santos Martins
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - B Dirkse
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - S Wehner
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
| | - R Hanson
- QuTech, Delft University of Technology, 2628 CJ Delft, Netherlands. .,Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands
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16
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Huang D, Abulnaga A, Welinski S, Raha M, Thompson JD, de Leon NP. Hybrid III-V diamond photonic platform for quantum nodes based on neutral silicon vacancy centers in diamond. OPTICS EXPRESS 2021; 29:9174-9189. [PMID: 33820350 DOI: 10.1364/oe.418081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Integrating atomic quantum memories based on color centers in diamond with on-chip photonic devices would enable entanglement distribution over long distances. However, efforts towards integration have been challenging because color centers can be highly sensitive to their environment, and their properties degrade in nanofabricated structures. Here, we describe a heterogeneously integrated, on-chip, III-V diamond platform designed for neutral silicon vacancy (SiV0) centers in diamond that circumvents the need for etching the diamond substrate. Through evanescent coupling to SiV0 centers near the surface of diamond, the platform will enable Purcell enhancement of SiV0 emission and efficient frequency conversion to the telecommunication C-band. The proposed structures can be realized with readily available fabrication techniques.
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17
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Local and Non-Local Invasive Measurements on Two Quantum Spins Coupled via Nanomechanical Oscillations. Symmetry (Basel) 2020. [DOI: 10.3390/sym12071078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Symmetry plays the central role in the structure of quantum states of bipartite (or many-body) fermionic systems. Typically, symmetry leads to the phenomenon of quantum coherence and correlations (entanglement) inherent to quantum systems only. In the present work, we study the role of symmetry (i.e., quantum correlations) in invasive quantum measurements. We consider the influence of a direct or indirect measurement process on a composite quantum system. We derive explicit analytical expressions for the case of two quantum spins positioned on both sides of the quantum cantilever. The spins are coupled indirectly to each others via their interaction with a magnetic tip deposited on the cantilever. Two types of quantum witnesses can be considered, which quantify the invasiveness of a measurement on the systems’ quantum states: (i) A local quantum witness stands for the consequence on the quantum spin states of a measurement done on the cantilever, meaning we first perform a measurement on the cantilever, and subsequently a measurement on a spin. (ii) The non-local quantum witness signifies the response of one spin if a measurement is done on the other spin. In both cases the disturbance must involve the cantilever. However, in the first case, the spin-cantilever interaction is linear in the coupling constant Ω , where as in the second case, the spin-spin interaction is quadratic in Ω . For both cases, we find and discuss analytical results for the witness.
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18
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van Leent T, Bock M, Garthoff R, Redeker K, Zhang W, Bauer T, Rosenfeld W, Becher C, Weinfurter H. Long-Distance Distribution of Atom-Photon Entanglement at Telecom Wavelength. PHYSICAL REVIEW LETTERS 2020; 124:010510. [PMID: 31976687 DOI: 10.1103/physrevlett.124.010510] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Indexed: 06/10/2023]
Abstract
Entanglement between stationary quantum memories and photonic channels is the essential resource for future quantum networks. Together with entanglement distillation, it will enable efficient distribution of quantum states. We report on the generation and observation of entanglement between a ^{87}Rb atom and a photon at telecom wavelength transmitted through up to 20 km of optical fiber. For this purpose, we use polarization-preserving quantum frequency conversion to transform the wavelength of a photon entangled with the atomic spin state from 780 nm to the telecom S band at 1522 nm. We achieve an unprecedented external device conversion efficiency of 57% and observe an entanglement fidelity between the atom and telecom photon of ≥78.5±0.9% after transmission through 20 km of optical fiber, mainly limited by decoherence of the atomic state. This result is an important milestone on the road to distribute quantum information on a large scale.
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Affiliation(s)
- Tim van Leent
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Matthias Bock
- Fachrichtung Physik, Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany
| | - Robert Garthoff
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Kai Redeker
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Wei Zhang
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
| | - Tobias Bauer
- Fachrichtung Physik, Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany
| | - Wenjamin Rosenfeld
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
- Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching, Germany
| | - Christoph Becher
- Fachrichtung Physik, Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany
| | - Harald Weinfurter
- Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstraße 4, 80799 München, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, 80799 München, Germany
- Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching, Germany
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