1
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Thomas P, Ruscio L, Morin O, Rempe G. Fusion of deterministically generated photonic graph states. Nature 2024; 629:567-572. [PMID: 38720079 PMCID: PMC11096110 DOI: 10.1038/s41586-024-07357-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 03/26/2024] [Indexed: 05/18/2024]
Abstract
Entanglement has evolved from an enigmatic concept of quantum physics to a key ingredient of quantum technology. It explains correlations between measurement outcomes that contradict classical physics and has been widely explored with small sets of individual qubits. Multi-partite entangled states build up in gate-based quantum-computing protocols and-from a broader perspective-were proposed as the main resource for measurement-based quantum-information processing1,2. The latter requires the ex-ante generation of a multi-qubit entangled state described by a graph3-6. Small graph states such as Bell or linear cluster states have been produced with photons7-16, but the proposed quantum-computing and quantum-networking applications require fusion of such states into larger and more powerful states in a programmable fashion17-21. Here we achieve this goal by using an optical resonator22 containing two individually addressable atoms23,24. Ring25 and tree26 graph states with up to eight qubits, with the names reflecting the entanglement topology, are efficiently fused from the photonic states emitted by the individual atoms. The fusion process itself uses a cavity-assisted gate between the two atoms. Our technique is, in principle, scalable to even larger numbers of qubits and is the decisive step towards, for instance, a memory-less quantum repeater in a future quantum internet27-29.
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Affiliation(s)
- Philip Thomas
- Max-Planck-Institut für Quantenoptik, Garching, Germany
| | | | - Olivier Morin
- Max-Planck-Institut für Quantenoptik, Garching, Germany.
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Garching, Germany
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2
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Descamps É, Keller A, Milman P. Gottesman-Kitaev-Preskill Encoding in Continuous Modal Variables of Single Photons. Phys Rev Lett 2024; 132:170601. [PMID: 38728710 DOI: 10.1103/physrevlett.132.170601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/28/2024] [Indexed: 05/12/2024]
Abstract
GKP states, introduced by Gottesman, Kitaev, and Preskill, are continuous variable logical qubits that can be corrected for errors caused by phase space displacements. Their experimental realization is challenging, in particular, using propagating fields, where quantum information is encoded in the quadratures of the electromagnetic field. However, traveling photons are essential in many applications of GKP codes involving the long-distance transmission of quantum information. We introduce a new method for encoding GKP states in propagating fields using single photons, each occupying a distinct auxiliary mode given by the propagation direction. The GKP states are defined as highly correlated states described by collective continuous modes, as time and frequency. We analyze how the error detection and correction protocol scales with the total photon number and the spectral width. We show that the obtained code can be corrected for displacements in time-frequency phase space, which correspond to dephasing, or rotations, in the quadrature phase space and to photon losses. Most importantly, we show that generating two-photon GKP states is relatively simple, and that such states are currently produced and manipulated in several photonic platforms where frequency and time-bin biphoton entangled states can be engineered.
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Affiliation(s)
- Éloi Descamps
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, CNRS UMR 7162, 75013 Paris, France
| | - Arne Keller
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, CNRS UMR 7162, 75013 Paris, France
- Department de Physique, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Pérola Milman
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, CNRS UMR 7162, 75013 Paris, France
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3
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Chen S, Peng LC, Guo YP, Gu XM, Ding X, Liu RZ, Zhao JY, You X, Qin J, Wang YF, He YM, Renema JJ, Huo YH, Wang H, Lu CY, Pan JW. Heralded Three-Photon Entanglement from a Single-Photon Source on a Photonic Chip. Phys Rev Lett 2024; 132:130603. [PMID: 38613293 DOI: 10.1103/physrevlett.132.130603] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/22/2024] [Indexed: 04/14/2024]
Abstract
In the quest to build general-purpose photonic quantum computers, fusion-based quantum computation has risen to prominence as a promising strategy. This model allows a ballistic construction of large cluster states which are universal for quantum computation, in a scalable and loss-tolerant way without feed forward, by fusing many small n-photon entangled resource states. However, a key obstacle to this architecture lies in efficiently generating the required essential resource states on photonic chips. One such critical seed state that has not yet been achieved is the heralded three-photon Greenberger-Horne-Zeilinger (3-GHZ) state. Here, we address this elementary resource gap, by reporting the first experimental realization of a heralded 3-GHZ state. Our implementation employs a low-loss and fully programmable photonic chip that manipulates six indistinguishable single photons of wavelengths in the telecommunication regime. Conditional on the heralding detection, we obtain the desired 3-GHZ state with a fidelity 0.573±0.024. Our Letter marks an important step for the future fault-tolerant photonic quantum computing, leading to the acceleration of building a large-scale optical quantum computer.
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Affiliation(s)
- Si Chen
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Li-Chao Peng
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Y-P Guo
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - X-M Gu
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - X Ding
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - R-Z 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - J-Y Zhao
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - X You
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- University of Science and Technology of China, School of Cyberspace Security, Hefei, China
| | - J Qin
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Y-F 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Yu-Ming He
- 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Jelmer J Renema
- QuiX Quantum B.V., Hengelosestraat 500, 7521 AN Enschede, The Netherlands
| | - 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Hui 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Chao-Yang 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, 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
- Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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4
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Cao H, Hansen LM, Giorgino F, Carosini L, Zahálka P, Zilk F, Loredo JC, Walther P. Photonic Source of Heralded Greenberger-Horne-Zeilinger States. Phys Rev Lett 2024; 132:130604. [PMID: 38613278 DOI: 10.1103/physrevlett.132.130604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 02/22/2024] [Indexed: 04/14/2024]
Abstract
Generating large multiphoton entangled states is of main interest due to enabling universal photonic quantum computing and all-optical quantum repeater nodes. These applications exploit measurement-based quantum computation using cluster states. Remarkably, it was shown that photonic cluster states of arbitrary size can be generated by using feasible heralded linear optics fusion gates that act on heralded three-photon Greenberger-Horne-Zeilinger (GHZ) states as the initial resource state. Thus, the capability of generating heralded GHZ states is of great importance for scaling up photonic quantum computing. Here, we experimentally demonstrate this required building block by reporting a polarisation-encoded heralded GHZ state of three photons, for which we build a high-rate six-photon source (547±2 Hz) from a solid-state quantum emitter and a stable polarization-based interferometer. The detection of three ancillary photons heralds the generation of three-photon GHZ states among the remaining particles with fidelities up to F=0.7278±0.0106. Our results initiate a path for scalable entangling operations using heralded linear-optics implementations.
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Affiliation(s)
- H Cao
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - L M Hansen
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - F Giorgino
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - L Carosini
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - P Zahálka
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - F Zilk
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - J C Loredo
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - P Walther
- University of Vienna, Faculty of Physics, Vienna Center for Quantum Science and Technology (VCQ), 1090 Vienna, Austria
- Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
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5
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Yang J, Chen Y, Rao Z, Zheng Z, Song C, Chen Y, Xiong K, Chen P, Zhang C, Wu W, Yu Y, Yu S. Tunable quantum dots in monolithic Fabry-Perot microcavities for high-performance single-photon sources. Light Sci Appl 2024; 13:33. [PMID: 38291018 PMCID: PMC10828388 DOI: 10.1038/s41377-024-01384-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/05/2024] [Accepted: 01/15/2024] [Indexed: 02/01/2024]
Abstract
Cavity-enhanced single quantum dots (QDs) are the main approach towards ultra-high-performance solid-state quantum light sources for scalable photonic quantum technologies. Nevertheless, harnessing the Purcell effect requires precise spectral and spatial alignment of the QDs' emission with the cavity mode, which is challenging for most cavities. Here we have successfully integrated miniaturized Fabry-Perot microcavities with a piezoelectric actuator, and demonstrated a bright single-photon source derived from a deterministically coupled QD within this microcavity. Leveraging the cavity-membrane structures, we have achieved large spectral tunability via strain tuning. On resonance, a high Purcell factor of ~9 is attained. The source delivers single photons with simultaneous high extraction efficiency of 0.58, high purity of 0.956(2) and high indistinguishability of 0.922(4). Together with its compact footprint, our scheme facilitates the scalable integration of indistinguishable quantum light sources on-chip, therefore removing a major barrier to the development of solid-state quantum information platforms based on QDs.
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Affiliation(s)
- Jiawei Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yan Chen
- Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha, 410073, China
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, 410073, China
- Hunan Key Laboratory of Quantum Information Mechanism and Technology, National University of Defense Technology, Changsha, 410073, Hunan, China
| | - Zhixuan Rao
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Ziyang Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Changkun Song
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yujie Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Kaili Xiong
- Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha, 410073, China
- Hunan Key Laboratory of Quantum Information Mechanism and Technology, National University of Defense Technology, Changsha, 410073, Hunan, China
| | - Pingxing Chen
- Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha, 410073, China
- Hunan Key Laboratory of Quantum Information Mechanism and Technology, National University of Defense Technology, Changsha, 410073, Hunan, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Chaofan Zhang
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, 410073, China
| | - Wei Wu
- Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha, 410073, China
- Hunan Key Laboratory of Quantum Information Mechanism and Technology, National University of Defense Technology, Changsha, 410073, Hunan, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China.
- Hefei National Laboratory, Hefei, 230088, China.
| | - Siyuan Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, 510006, China
- Hefei National Laboratory, Hefei, 230088, China
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6
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Santos AC, Schneider C, Bachelard R, Predojević A, Antón-Solanas C. Multipartite entanglement encoded in the photon-number basis by sequential excitation of a three-level system. Opt Lett 2023; 48:6332-6335. [PMID: 38039260 DOI: 10.1364/ol.506403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/14/2023] [Indexed: 12/03/2023]
Abstract
We propose a general scheme to generate entanglement encoded in the photon-number basis, via a sequential resonant two-photon excitation of a three-level system. We apply it to the specific case of a quantum dot three-level system, which can emit a photon pair through a biexciton-exciton cascade. The state generated in our scheme constitutes a tool for secure communication, as the multipartite correlations present in the produced state may provide an enhanced rate of secret communication with respect to a perfect GHZ state.
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7
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Carollo F. Non-Gaussian Dynamics of Quantum Fluctuations and Mean-Field Limit in Open Quantum Central Spin Systems. Phys Rev Lett 2023; 131:227102. [PMID: 38101340 DOI: 10.1103/physrevlett.131.227102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/10/2023] [Accepted: 11/01/2023] [Indexed: 12/17/2023]
Abstract
Central spin systems, in which a central spin is singled out and interacts nonlocally with several bath spins, are paradigmatic models for nitrogen-vacancy centers and quantum dots. They show complex emergent dynamics and stationary phenomena which, despite the collective nature of their interaction, are still largely not understood. Here, we derive exact results on the emergent behavior of open quantum central spin systems. The latter crucially depends on the scaling of the interaction strength with the bath size. For scalings with the inverse square root of the bath size (typical of one-to-many interactions), the system behaves, in the thermodynamic limit, as an open quantum Jaynes-Cummings model, whose bosonic mode encodes the quantum fluctuations of the bath spins. In this case, non-Gaussian correlations are dynamically generated and persist at stationarity. For scalings with the inverse bath size, the emergent dynamics is instead of mean-field type. Our Letter provides a fundamental understanding of the different dynamical regimes of central spin systems and a simple theory for efficiently exploring their nonequilibrium behavior. Our findings may become relevant for developing fully quantum descriptions of many-body solid-state devices and their applications.
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Affiliation(s)
- Federico Carollo
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
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8
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Yu Y, Liu S, Lee CM, Michler P, Reitzenstein S, Srinivasan K, Waks E, Liu J. Telecom-band quantum dot technologies for long-distance quantum networks. Nat Nanotechnol 2023; 18:1389-1400. [PMID: 38049595 DOI: 10.1038/s41565-023-01528-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 09/15/2023] [Indexed: 12/06/2023]
Abstract
A future quantum internet is expected to generate, distribute, store and process quantum bits (qubits) over the world by linking different quantum nodes via quantum states of light. To facilitate long-haul operations, quantum repeaters must operate at telecom wavelengths to take advantage of both the low-loss optical fibre network and the established technologies of modern optical communications. Semiconductor quantum dots have thus far shown exceptional performance as key elements for quantum repeaters, such as quantum light sources and spin-photon interfaces, but only in the near-infrared regime. Therefore, the development of high-performance telecom-band quantum dot devices is highly desirable for a future solid-state quantum internet based on fibre networks. In this Review, we present the physics and technological developments towards epitaxial quantum dot devices emitting in the telecom O- and C-bands for quantum networks, considering both advanced epitaxial growth for direct telecom emission and quantum frequency conversion for telecom-band down-conversion of near-infrared quantum dot devices. We also discuss the challenges and opportunities for future realization of telecom quantum dot devices with improved performance and expanded functionality through hybrid integration.
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Affiliation(s)
- Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, School of Physics, Sun Yat-sen University, Guangzhou, China
| | - Shunfa Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, School of Physics, Sun Yat-sen University, Guangzhou, China
| | - Chang-Min Lee
- Department of Electrical and Computer Engineering and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Peter Michler
- Institut für Halbleiteroptik und Funktionelle Grenzflächen (IHFG), Center for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Stuttgart, Germany
| | - Stephan Reitzenstein
- Institute of Solid State Physics, Technische Universität Berlin, Berlin, Germany
| | - Kartik Srinivasan
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
- Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Edo Waks
- Department of Electrical and Computer Engineering and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
- Joint Quantum Institute, NIST/University of Maryland, College Park, MD, USA
| | - Jin Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, School of Physics, Sun Yat-sen University, Guangzhou, China.
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9
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Kirstein E, Smirnov DS, Zhukov EA, Yakovlev DR, Kopteva NE, Dirin DN, Hordiichuk O, Kovalenko MV, Bayer M. The squeezed dark nuclear spin state in lead halide perovskites. Nat Commun 2023; 14:6683. [PMID: 37865649 PMCID: PMC10590392 DOI: 10.1038/s41467-023-42265-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023] Open
Abstract
Coherent many-body states are highly promising for robust quantum information processing. While far-reaching theoretical predictions have been made for various implementations, direct experimental evidence of their appealing properties can be challenging. Here, we demonstrate optical manipulation of the nuclear spin ensemble in the lead halide perovskite semiconductor FAPbBr3 (FA = formamidinium), targeting a long-postulated collective dark state that is insensitive to optical pumping after its build-up. Via optical orientation of localized hole spins we drive the nuclear many-body system into this entangled state, requiring a weak magnetic field of only a few milli-Tesla strength at cryogenic temperatures. During its fast establishment, the nuclear polarization along the optical axis remains small, while the transverse nuclear spin fluctuations are strongly reduced, corresponding to spin squeezing as evidenced by a strong violation of the generalized nuclear squeezing-inequality with ξs < 0.5. The dark state corresponds to an ~35-body entanglement between the nuclei. Dark nuclear spin states can be exploited to store quantum information benefiting from their long-lived many-body coherence and to perform quantum measurements with a precision beyond the standard limit.
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Affiliation(s)
- E Kirstein
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany.
| | - D S Smirnov
- Ioffe Institute, 194021, St. Petersburg, Russia.
| | - E A Zhukov
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - D R Yakovlev
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - N E Kopteva
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - D N Dirin
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - O Hordiichuk
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - M V Kovalenko
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - M Bayer
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
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10
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Paesani S, Brown BJ. High-Threshold Quantum Computing by Fusing One-Dimensional Cluster States. Phys Rev Lett 2023; 131:120603. [PMID: 37802959 DOI: 10.1103/physrevlett.131.120603] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 07/11/2023] [Indexed: 10/08/2023]
Abstract
We propose a measurement-based model for fault-tolerant quantum computation that can be realized with one-dimensional cluster states and fusion measurements only; basic resources that are readily available with scalable photonic hardware. Our simulations demonstrate high thresholds compared with other measurement-based models realized with basic entangled resources and 2-qubit fusion measurements. Its high tolerance to noise indicates that our practical construction offers a promising route to scalable quantum computing with quantum emitters and linear-optical elements.
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Affiliation(s)
- Stefano Paesani
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen 2100, Denmark
- NNF Quantum Computing Programme, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen 2100, Denmark
| | - Benjamin J Brown
- IBM Quantum, T. J. Watson Research Center, Yorktown Heights, New York 10598, USA
- IBM Denmark, Prøvensvej 1, Brøndby 2605, Denmark
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11
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Dey AB, Sanyal MK, Schropp A, Achilles S, Keller TF, Farrer I, Ritchie DA, Bertram F, Schroer CG, Seeck OH. Culling a Self-Assembled Quantum Dot as a Single-Photon Source Using X-ray Microscopy. ACS Nano 2023; 17:16080-16088. [PMID: 37523736 PMCID: PMC10763734 DOI: 10.1021/acsnano.3c04835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/27/2023] [Indexed: 08/02/2023]
Abstract
Epitaxially grown self-assembled semiconductor quantum dots (QDs) with atom-like optical properties have emerged as the best choice for single-photon sources required for the development of quantum technology and quantum networks. Nondestructive selection of a single QD having desired structural, compositional, and optical characteristics is essential to obtain noise-free, fully indistinguishable single or entangled photons from single-photon emitters. Here, we show that the structural orientations and local compositional inhomogeneities within a single QD and the surrounding wet layer can be probed in a screening fashion by scanning X-ray diffraction microscopy and X-ray fluorescence with a few tens of nanometers-sized synchrotron radiation beam. The presented measurement protocol can be used to cull the best single QD from the enormous number of self-assembled dots grown simultaneously. The obtained results show that the elemental composition and resultant strain profiles of a QD are sensitive to in-plane crystallographic directions. We also observe that lattice expansion after a certain composition-limit introduces shear strain within a QD, enabling the possibility of controlled chiral-QD formation. Nanoscale chirality and compositional anisotropy, contradictory to common assumptions, need to be incorporated into existing theoretical models to predict the optical properties of single-photon sources and to further tune the epitaxial growth process of self-assembled quantum structures.
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Affiliation(s)
- Arka Bikash Dey
- Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Milan K. Sanyal
- Surface
Physics and Material Science Division, Saha
Institute of Nuclear Physics, Kolkata, West Bengal 700064, India
| | - Andreas Schropp
- Center
for X-ray and Nano Science CXNS, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
| | - Silvio Achilles
- Center
for X-ray and Nano Science CXNS, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
| | - Thomas F. Keller
- Center
for X-ray and Nano Science CXNS, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
- Physics
Department, University of Hamburg, Hamburg 20355, Germany
| | - Ian Farrer
- Department
of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, United Kingdom
| | - David A. Ritchie
- Cavendish
Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Florian Bertram
- Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Christian G. Schroer
- Center
for X-ray and Nano Science CXNS, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
| | - Oliver H. Seeck
- Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
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12
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Chiang TM, Schatz GC. Theory of entangled two-photon emission/absorption [E2P-EA] between molecules. J Chem Phys 2023; 159:074103. [PMID: 37581420 DOI: 10.1063/5.0156501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 07/25/2023] [Indexed: 08/16/2023] Open
Abstract
This paper presents a comprehensive study of the theory of entangled two-photon emission/absorption (E2P-EA) between a many-level cascade donor and a many-level acceptor (which could be quantum dots or molecules) using second-order perturbation theory and where the donor-acceptor pair is in a homogeneous but dispersive medium. To understand the mechanism of E2P-EA, we analyze how dipole orientation, radiative lifetime, energy detuning between intermediate states, separation distance, and entanglement time impact the E2P-EA rate. Our study shows that there are quantum interference effects in the E2P-EA rate expression that lead to oscillations in the rate as a function of entanglement time. Furthermore, we find that the E2P-EA rate for a representative system consisting of two quantum dots can be comparable to one-photon emission/absorption (OP-EA) when donor and acceptor are within a few nm. However, the E2P-EA rate falls off much more quickly with separation distance than does OP-EA.
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Affiliation(s)
- Tse-Min Chiang
- Graduate Program in Applied Physics, Northwestern University, Evanston, Illinois 60208, USA
| | - George C Schatz
- Department of Chemistry and Graduate Program in Applied Physics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA
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13
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Antoniadis NO, Hogg MR, Stehl WF, Javadi A, Tomm N, Schott R, Valentin SR, Wieck AD, Ludwig A, Warburton RJ. Cavity-enhanced single-shot readout of a quantum dot spin within 3 nanoseconds. Nat Commun 2023; 14:3977. [PMID: 37407552 DOI: 10.1038/s41467-023-39568-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/14/2023] [Indexed: 07/07/2023] Open
Abstract
Rapid, high-fidelity single-shot readout of quantum states is a ubiquitous requirement in quantum information technologies. For emitters with a spin-preserving optical transition, spin readout can be achieved by driving the transition with a laser and detecting the emitted photons. The speed and fidelity of this approach is typically limited by low photon collection rates and measurement back-action. Here we use an open microcavity to enhance the optical readout signal from a semiconductor quantum dot spin state, largely overcoming these limitations. We achieve single-shot readout of an electron spin in only 3 nanoseconds with a fidelity of (95.2 ± 0.7)%, and observe quantum jumps using repeated single-shot measurements. Owing to the speed of our readout, errors resulting from measurement-induced back-action have minimal impact. Our work reduces the spin readout-time well below both the achievable spin relaxation and dephasing times in semiconductor quantum dots, opening up new possibilities for their use in quantum technologies.
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Affiliation(s)
- Nadia O Antoniadis
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Mark R Hogg
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
| | - Willy F Stehl
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Alisa Javadi
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
- School of Electrical and Computer Engineering, Department of Physics and Astronomy, The University of Oklahoma, 110 West Boyd Street, Norman, OK, 73019, USA
| | - Natasha Tomm
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Rüdiger Schott
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany
| | - Sascha R Valentin
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
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14
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Bantysh B, Katamadze K, Chernyavskiy A, Bogdanov Y. Fast reconstruction of programmable integrated interferometers. Opt Express 2023; 31:16729-16742. [PMID: 37157746 DOI: 10.1364/oe.487156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Programmable linear optical interferometers are important for classical and quantum information technologies, as well as for building hardware-accelerated artificial neural networks. Recent results showed the possibility of constructing optical interferometers that could implement arbitrary transformations of input fields even in the case of high manufacturing errors. The building of detailed models of such devices drastically increases the efficiency of their practical use. The integral design of interferometers complicates its reconstruction since the internal elements are hard to address. This problem can be approached by using optimization algorithms [Opt. Express29, 38429 (2021)10.1364/OE.432481]. In this paper, we present what we believe to be a novel efficient algorithm based on linear algebra only, which does not use computationally expensive optimization procedures. We show that this approach makes it possible to perform fast and accurate characterization of high-dimensional programmable integrated interferometers. Moreover, the method provides access to the physical characteristics of individual interferometer layers.
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15
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Nasiri Avanaki K, Schatz GC. Generation of entangled-photons by a quantum dot cascade source in polarized cavities: Using cavity resonances to boost signals and preserve the entanglements. J Chem Phys 2023; 158:144106. [PMID: 37061505 DOI: 10.1063/5.0144364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023] Open
Abstract
Motivated by recent advances in the development of single photon emitters for quantum information sciences, here we design and formulate a quantum cascade model that describes cascade emission by a quantum dot (QD) in a cavity structure while preserving entanglement that stores information needed for single photon emission. The theoretical approach is based on a photonic structure that consists of two orthogonal cavities in which resonance with either the first or second of the two emitted photons is possible, leading to amplification and rerouting of the entangled light. The cavity-QD scheme uses a four-level cascade emitter that involves three levels for each polarization, leading to two spatially entangled photons for each polarization. By solving the Schrodinger equation, we identify the characteristic properties of the system, which can be used in conjunction with optimization techniques to achieve the "best" design relative to a set of prioritized criteria or constraints in our optical system. The theoretical investigations include an analysis of emission spectra in addition to the joint spectral density profile, and the results demonstrate the ability of the cavities to act as frequency filters for the photons that make up the entanglements and to modify entanglement properties. The results provide new opportunities for the experimental design and engineering of on-demand single photon sources.
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Affiliation(s)
- K Nasiri Avanaki
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - George C Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
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16
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Saleem Y, Sadecka K, Korkusinski M, Miravet D, Dusko A, Hawrylak P. Theory of Excitons in Gated Bilayer Graphene Quantum Dots. Nano Lett 2023; 23:2998-3004. [PMID: 36962005 DOI: 10.1021/acs.nanolett.3c00406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We present a theory of excitons in gated bilayer graphene (BLG) quantum dots (QDs). Electrical gating of BLG opens an energy gap, turning this material into an electrically tunable semiconductor. Unlike in laterally gated semiconductor QDs, where electrons are attracted and holes repelled, we show here that lateral structuring of metallic gates results in a gated lateral QD confining both electrons and holes. Using an accurate atomistic approach and exact diagonalization tools, we describe strongly interacting electrons and holes forming an electrically tunable exciton. We find these excitons to be different from those found in semiconductor QDs and nanocrystals, with exciton energy tunable by voltage from the terahertz to far infrared (FIR) range. The conservation of spin, valley, and orbital angular momentum results in an exciton fine structure with a band of dark low-energy states, making this system a promising candidate for storage, detection and emission of photons in the terahertz range.
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Affiliation(s)
- Yasser Saleem
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
| | - Katarzyna Sadecka
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
- Institute of Theoretical Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Marek Korkusinski
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
- Security and Disruptive Technologies, National Research Council, Ottawa K1A0R6, Canada
| | - Daniel Miravet
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
| | - Amintor Dusko
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
| | - Pawel Hawrylak
- Department of Physics, University of Ottawa, Ottawa K1N6N5, Canada
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17
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Zaporski L, Shofer N, Bodey JH, Manna S, Gillard G, Appel MH, Schimpf C, Covre da Silva SF, Jarman J, Delamare G, Park G, Haeusler U, Chekhovich EA, Rastelli A, Gangloff DA, Atatüre M, Le Gall C. Ideal refocusing of an optically active spin qubit under strong hyperfine interactions. Nat Nanotechnol 2023; 18:257-263. [PMID: 36702953 DOI: 10.1038/s41565-022-01282-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/28/2022] [Indexed: 06/18/2023]
Abstract
Combining highly coherent spin control with efficient light-matter coupling offers great opportunities for quantum communication and computing. Optically active semiconductor quantum dots have unparalleled photonic properties but also modest spin coherence limited by their resident nuclei. The nuclear inhomogeneity has thus far bound all dynamical decoupling measurements to a few microseconds. Here, we eliminate this inhomogeneity using lattice-matched GaAs-AlGaAs quantum dot devices and demonstrate dynamical decoupling of the electron spin qubit beyond 0.113(3) ms. Leveraging the 99.30(5)% visibility of our optical π-pulse gates, we use up to Nπ = 81 decoupling pulses and find a coherence time scaling of [Formula: see text]. This scaling manifests an ideal refocusing of strong interactions between the electron and the nuclear spin ensemble, free of extrinsic noise, which holds the promise of lifetime-limited spin coherence. Our findings demonstrate that the most punishing material science challenge for such quantum dot devices has a remedy and constitute the basis for highly coherent spin-photon interfaces.
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Affiliation(s)
- Leon Zaporski
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
| | - Noah Shofer
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Jonathan H Bodey
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Santanu Manna
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Austria
- Department of Electrical Engineering, Indian Institute of Technology Delhi, New Delhi, India
| | - George Gillard
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | | | - Christian Schimpf
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Austria
| | | | - John Jarman
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Geoffroy Delamare
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Gunhee Park
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Urs Haeusler
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Evgeny A Chekhovich
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Armando Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz, Austria
| | - Dorian A Gangloff
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Mete Atatüre
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
| | - Claire Le Gall
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
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18
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Cogan D, Su ZE, Kenneth O, Gershoni D. Deterministic generation of indistinguishable photons in a cluster state. Nat Photonics 2023; 17:324-329. [PMID: 37064524 PMCID: PMC10091623 DOI: 10.1038/s41566-022-01152-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/19/2022] [Indexed: 06/19/2023]
Abstract
Entanglement between particles is a basic concept of quantum sciences. The ability to produce entangled particles in a controllable manner is essential for any quantum technology. Entanglement between light particles (photons) is particularly crucial for quantum communication due to light's non-interactive nature and long-lasting coherence. Resources producing entangled multiphoton cluster states will enable communication between remote quantum nodes, as the inbuilt redundancy of cluster photons allows for repeated local measurements-compensating for losses and probabilistic Bell measurements. For feasible applications, the cluster generation should be fast, deterministic and, most importantly, its photons indistinguishable, which will allow measurements and fusion of clusters by interfering photons. Here, using periodic excitation of a semiconductor quantum-dot-confined spin, we demonstrate a multi-indistinguishable photon cluster, featuring a continuously generated string of photons at deterministic gigahertz generation rates, and an optimized entanglement length of about ten photons. The indistinguishability of the photons opens up new possibilities for scaling up the cluster's dimensionality by fusion, thus building graph states suited for measurement-based photonic quantum computers and all-photonic quantum repeaters.
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Affiliation(s)
- Dan Cogan
- The Physics Department and the Solid State Institute, Technion — Israel Institute of Technology, Haifa, Israel
| | - Zu-En Su
- The Physics Department and the Solid State Institute, Technion — Israel Institute of Technology, Haifa, Israel
| | - Oded Kenneth
- The Physics Department and the Solid State Institute, Technion — Israel Institute of Technology, Haifa, Israel
| | - David Gershoni
- The Physics Department and the Solid State Institute, Technion — Israel Institute of Technology, Haifa, Israel
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19
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Puzantian B, Saleem Y, Korkusinski M, Hawrylak P. Edge States and Strain-Driven Topological Phase Transitions in Quantum Dots in Topological Insulators. Nanomaterials (Basel) 2022; 12:4283. [PMID: 36500906 PMCID: PMC9735616 DOI: 10.3390/nano12234283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
We present here a theory of the electronic properties of quasi two-dimensional quantum dots made of topological insulators. The topological insulator is described by either eight band k→·p→ Hamiltonian or by a four-band k→·p→ Bernevig-Hughes-Zhang (BHZ) Hamiltonian. The trivial versus topological properties of the BHZ Hamiltonian are characterized by the different topologies that arise when mapping the in-plane wavevectors through the BHZ Hamiltonian onto a Bloch sphere. In the topologically nontrivial case, edge states are formed in the disc and square geometries of the quantum dot. We account for the effects of compressive strain in topological insulator quantum dots by means of the Bir-Pikus Hamiltonian. Tuning strain allows topological phase transitions between topological and trivial phases, which results in the vanishing of edge states from the energy gap. This may enable the design of a quantum strain sensor based on strain-driven transitions in HgTe topological insulator square quantum dots.
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Affiliation(s)
| | - Yasser Saleem
- Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Marek Korkusinski
- Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Quantum Theory Group, Security and Disruptive Technologies, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Pawel Hawrylak
- Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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20
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Zheng W, Xiang L, de Quesada FA, Augustin M, Lu Z, Wilson M, Sood A, Wu F, Shcherbakov D, Memaran S, Baumbach RE, McCandless GT, Chan JY, Liu S, Edgar JH, Lau CN, Lui CH, Santos EJG, Lindenberg A, Smirnov D, Balicas L. Thickness- and Twist-Angle-Dependent Interlayer Excitons in Metal Monochalcogenide Heterostructures. ACS Nano 2022; 16:18695-18707. [PMID: 36257051 DOI: 10.1021/acsnano.2c07394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Interlayer excitons, or bound electron-hole pairs whose constituent quasiparticles are located in distinct stacked semiconducting layers, are being intensively studied in heterobilayers of two-dimensional semiconductors. They owe their existence to an intrinsic type-II band alignment between both layers that convert these into p-n junctions. Here, we unveil a pronounced interlayer exciton (IX) in heterobilayers of metal monochalcogenides, namely, γ-InSe on ε-GaSe, whose pronounced emission is adjustable just by varying their thicknesses given their number of layers dependent direct band gaps. Time-dependent photoluminescense spectroscopy unveils considerably longer interlayer exciton lifetimes with respect to intralayer ones, thus confirming their nature. The linear Stark effect yields a bound electron-hole pair whose separation d is just (3.6 ± 0.1) Å with d being very close to dSe = 3.4 Å which is the calculated interfacial Se separation. The envelope of IX is twist-angle-dependent and describable by superimposed emissions that are nearly equally spaced in energy, as if quantized due to localization induced by the small moiré periodicity. These heterostacks are characterized by extremely flat interfacial valence bands making them prime candidates for the observation of magnetism or other correlated electronic phases upon carrier doping.
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Affiliation(s)
- Wenkai Zheng
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Li Xiang
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Felipe A de Quesada
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California94025, United States
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Mathias Augustin
- Institute for Condensed Matter Physics and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, EdinburghEH9 3FD, United Kingdom
- Higgs Centre for Theoretical Physics, The University of Edinburgh, EdinburghEH9 3FD, United Kingdom
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Matthew Wilson
- Department of Physics and Astronomy, University of California, Riverside, California92521, United States
| | - Aditya Sood
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California94025, United States
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Fengcheng Wu
- School of Physics and Technology, Wuhan University, Wuhan, 430072China
| | - Dmitry Shcherbakov
- Department of Physics, The Ohio State University, Columbus, Ohio43210, United States
| | - Shahriar Memaran
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Ryan E Baumbach
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Gregory T McCandless
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas76798, United States
| | - Julia Y Chan
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas76798, United States
| | - Song Liu
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, Kansas66506, United States
| | - James H Edgar
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, Kansas66506, United States
| | - Chun Ning Lau
- Department of Physics, The Ohio State University, Columbus, Ohio43210, United States
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, California92521, United States
| | - Elton J G Santos
- Institute for Condensed Matter Physics and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, EdinburghEH9 3FD, United Kingdom
- Higgs Centre for Theoretical Physics, The University of Edinburgh, EdinburghEH9 3FD, United Kingdom
- Donostia International Physics Centre, 20018Donostia-San Sebastian, Spain
| | - Aaron Lindenberg
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California94025, United States
- Department of Materials Science and Engineering, Stanford University, Stanford, California94305, United States
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
| | - Luis Balicas
- National High Magnetic Field Laboratory, Tallahassee, Florida32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida32306, United States
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21
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Stas PJ, Huan YQ, Machielse B, Knall EN, Suleymanzade A, Pingault B, Sutula M, Ding SW, Knaut CM, Assumpcao DR, Wei YC, Bhaskar MK, Riedinger R, Sukachev DD, Park H, Lončar M, Levonian DS, Lukin MD. Robust multi-qubit quantum network node with integrated error detection. Science 2022; 378:557-560. [DOI: 10.1126/science.add9771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Long-distance quantum communication and networking require quantum memory nodes with efficient optical interfaces and long memory times. We report the realization of an integrated two-qubit network node based on silicon-vacancy centers (SiVs) in diamond nanophotonic cavities. Our qubit register consists of the SiV electron spin acting as a communication qubit and the strongly coupled silicon-29 nuclear spin acting as a memory qubit with a quantum memory time exceeding 2 seconds. By using a highly strained SiV, we realize electron-photon entangling gates at temperatures up to 1.5 kelvin and nucleus-photon entangling gates up to 4.3 kelvin. We also demonstrate efficient error detection in nuclear spin–photon gates by using the electron spin as a flag qubit, making this platform a promising candidate for scalable quantum repeaters.
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Affiliation(s)
- P.-J. Stas
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Y. Q. Huan
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - B. Machielse
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- AWS Center for Quantum Networking, Boston, MA 02210, USA
| | - E. N. Knall
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - A. Suleymanzade
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - B. Pingault
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- QuTech, Delft University of Technology, 2600 GA Delft, Netherlands
- Kavli Institute of Nanoscience Delft, Delft University of Technology, 2600 GA Delft, Netherlands
| | - M. Sutula
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - S. W. Ding
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - C. M. Knaut
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - D. R. Assumpcao
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Y.-C. Wei
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - M. K. Bhaskar
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- AWS Center for Quantum Networking, Boston, MA 02210, USA
| | - R. Riedinger
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- Institut für Laserphysik und Zentrum für Optische Quantentechnologien, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, 22761 Hamburg, Germany
| | - D. D. Sukachev
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- AWS Center for Quantum Networking, Boston, MA 02210, USA
| | - H. Park
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - M. Lončar
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - D. S. Levonian
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
- AWS Center for Quantum Networking, Boston, MA 02210, USA
| | - M. D. Lukin
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
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22
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Singh H, Farfurnik D, Luo Z, Bracker AS, Carter SG, Waks E. Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity. Nano Lett 2022; 22:7959-7964. [PMID: 36129824 DOI: 10.1021/acs.nanolett.2c03098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Optically active spin systems coupled to photonic cavities with high cooperativity can generate strong light-matter interactions, a key ingredient in quantum networks. However, obtaining high cooperativities for quantum information processing often involves the use of photonic crystal cavities that feature a poor optical access from the free space, especially to circularly polarized light required for the coherent control of the spin. Here, we demonstrate coupling with a cooperativity as high as 8 of an InAs/GaAs quantum dot to a fabricated bullseye cavity that provides nearly degenerate and Gaussian polarization modes for efficient optical accessing. We observe spontaneous emission lifetimes of the quantum dot as short as 80 ps (an ∼15 Purcell enhancement) and a ∼80% transparency of light reflected from the cavity. Leveraging the induced transparency for photon switching while coherently controlling the quantum dot spin could contribute to ongoing efforts of establishing quantum networks.
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Affiliation(s)
- Harjot Singh
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Demitry Farfurnik
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Zhouchen Luo
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Allan S Bracker
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Samuel G Carter
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Edo Waks
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
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23
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Leppenen NV, Smirnov DS. Optical measurement of electron spins in quantum dots: quantum Zeno effects. Nanoscale 2022; 14:13284-13291. [PMID: 36062980 DOI: 10.1039/d2nr01241c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We describe theoretically the effects of the quantum back action under the continuous optical measurement of electron spins in quantum dots. We consider the system excitation by elliptically polarized light close to the trion resonance, which allows for simultaneous spin orientation and measurement. We microscopically demonstrate that the nuclei-induced spin relaxation can be both suppressed and accelerated by the continuous spin measurement due to the quantum Zeno and anti-Zeno effects, respectively. Our theoretical predictions can be directly compared with the future experimental results and straightforwardly generalized for pump-probe experiments.
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Affiliation(s)
| | - D S Smirnov
- Ioffe Institute, 194021 St. Petersburg, Russia.
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24
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Thomas P, Ruscio L, Morin O, Rempe G. Efficient generation of entangled multiphoton graph states from a single atom. Nature 2022; 608:677-81. [PMID: 36002484 DOI: 10.1038/s41586-022-04987-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/16/2022] [Indexed: 11/23/2022]
Abstract
The central technological appeal of quantum science resides in exploiting quantum effects, such as entanglement, for a variety of applications, including computing, communication and sensing1. The overarching challenge in these fields is to address, control and protect systems of many qubits against decoherence2. Against this backdrop, optical photons, naturally robust and easy to manipulate, represent ideal qubit carriers. However, the most successful technique so far for creating photonic entanglement3 is inherently probabilistic and, therefore, subject to severe scalability limitations. Here we report the implementation of a deterministic protocol4–6 for the creation of photonic entanglement with a single memory atom in a cavity7. We interleave controlled single-photon emissions with tailored atomic qubit rotations to efficiently grow Greenberger–Horne–Zeilinger (GHZ) states8 of up to 14 photons and linear cluster states9 of up to 12 photons with a fidelity lower bounded by 76(6)% and 56(4)%, respectively. Thanks to a source-to-detection efficiency of 43.18(7)% per photon, we measure these large states about once every minute, which is orders of magnitude faster than in any previous experiment3,10–13. In the future, this rate could be increased even further, the scheme could be extended to two atoms in a cavity14,15 or several sources could be quantum mechanically coupled16, to generate higher-dimensional cluster states17. Overcoming the limitations encountered by probabilistic schemes for photonic entanglement generation, our results may offer a way towards scalable measurement-based quantum computation18,19 and communication20,21. Using a single memory atom in a cavity, a deterministic protocol is implemented to efficiently grow Greenberger–Horne–Zeilinger and linear cluster states by means of single-photon emissions.
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25
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Knall EN, Knaut CM, Bekenstein R, Assumpcao DR, Stroganov PL, Gong W, Huan YQ, Stas PJ, Machielse B, Chalupnik M, Levonian D, Suleymanzade A, Riedinger R, Park H, Lončar M, Bhaskar MK, Lukin MD. Efficient Source of Shaped Single Photons Based on an Integrated Diamond Nanophotonic System. Phys Rev Lett 2022; 129:053603. [PMID: 35960557 DOI: 10.1103/physrevlett.129.053603] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
An efficient, scalable source of shaped single photons that can be directly integrated with optical fiber networks and quantum memories is at the heart of many protocols in quantum information science. We demonstrate a deterministic source of arbitrarily temporally shaped single-photon pulses with high efficiency [detection efficiency=14.9%] and purity [g^{(2)}(0)=0.0168] and streams of up to 11 consecutively detected single photons using a silicon-vacancy center in a highly directional fiber-integrated diamond nanophotonic cavity. Combined with previously demonstrated spin-photon entangling gates, this system enables on-demand generation of streams of correlated photons such as cluster states and could be used as a resource for robust transmission and processing of quantum information.
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Affiliation(s)
- E N Knall
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - C M Knaut
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - R Bekenstein
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - D R Assumpcao
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - P L Stroganov
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - W Gong
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Y Q Huan
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - P-J Stas
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - B Machielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - M Chalupnik
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - D Levonian
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - A Suleymanzade
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - R Riedinger
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Institut für Laserphysik und Zentrum für Optische Quantentechnologien, Universität Hamburg, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, 22761 Hamburg, Germany
| | - H Park
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M Lončar
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M K Bhaskar
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- AWS Center for Quantum Computing, Pasadena, California 91125, USA
| | - M D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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26
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Tran KX, Bracker AS, Yakes MK, Grim JQ, Carter SG. Enhanced Spin Coherence of a Self-Assembled Quantum Dot Molecule at the Optimal Electrical Bias. Phys Rev Lett 2022; 129:027403. [PMID: 35867431 DOI: 10.1103/physrevlett.129.027403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
A pair of coupled dots with one electron in each dot can provide improvements in spin coherence, particularly at an electrical bias called the "sweet spot," but few measurements have been performed on self-assembled dots in this regime. Here, we directly measure the T_{2}^{*} coherence time of the singlet-triplet states in this system as a function of bias and magnetic field, obtaining a maximum T_{2}^{*} of 60 ns, more than an order of magnitude higher than an electron spin in a single quantum dot. Our results uncover two main dephasing mechanisms: electrical noise away from the sweet spot, and a magnetic field dependent interaction with nuclear spins due to a difference in g factors.
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Affiliation(s)
- Kha X Tran
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Allan S Bracker
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Michael K Yakes
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Joel Q Grim
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Samuel G Carter
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
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27
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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. Phys Rev Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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28
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29
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Bluvstein D, Levine H, Semeghini G, Wang TT, Ebadi S, Kalinowski M, Keesling A, Maskara N, Pichler H, Greiner M, Vuletić V, Lukin MD. A quantum processor based on coherent transport of entangled atom arrays. Nature 2022; 604:451-456. [PMID: 35444318 PMCID: PMC9021024 DOI: 10.1038/s41586-022-04592-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/28/2022] [Indexed: 11/23/2022]
Abstract
The ability to engineer parallel, programmable operations between desired qubits within a quantum processor is key for building scalable quantum information systems1,2. In most state-of-the-art approaches, qubits interact locally, constrained by the connectivity associated with their fixed spatial layout. Here we demonstrate a quantum processor with dynamic, non-local connectivity, in which entangled qubits are coherently transported in a highly parallel manner across two spatial dimensions, between layers of single- and two-qubit operations. Our approach makes use of neutral atom arrays trapped and transported by optical tweezers; hyperfine states are used for robust quantum information storage, and excitation into Rydberg states is used for entanglement generation3–5. We use this architecture to realize programmable generation of entangled graph states, such as cluster states and a seven-qubit Steane code state6,7. Furthermore, we shuttle entangled ancilla arrays to realize a surface code state with thirteen data and six ancillary qubits8 and a toric code state on a torus with sixteen data and eight ancillary qubits9. Finally, we use this architecture to realize a hybrid analogue–digital evolution2 and use it for measuring entanglement entropy in quantum simulations10–12, experimentally observing non-monotonic entanglement dynamics associated with quantum many-body scars13,14. Realizing a long-standing goal, these results provide a route towards scalable quantum processing and enable applications ranging from simulation to metrology. A quantum processer is realized using arrays of neutral atoms that are transported in a parallel manner by optical tweezers during computations, and used for quantum error correction and simulations.
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Affiliation(s)
- Dolev Bluvstein
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Harry Levine
- Department of Physics, Harvard University, Cambridge, MA, USA.,AWS Center for Quantum Computing, Pasadena, CA, USA
| | | | - Tout T Wang
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Sepehr Ebadi
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Alexander Keesling
- Department of Physics, Harvard University, Cambridge, MA, USA.,QuEra Computing Inc., Boston, MA, USA
| | - Nishad Maskara
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hannes Pichler
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria.,Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Innsbruck, Austria
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Vladan Vuletić
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA, USA.
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30
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Varo S, Juska G, Pelucchi E. An intuitive protocol for polarization-entanglement restoral of quantum dot photon sources with non-vanishing fine-structure splitting. Sci Rep 2022; 12:4723. [PMID: 35304526 PMCID: PMC8933574 DOI: 10.1038/s41598-022-08535-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
Generation of polarization-entangled photons from quantum dots via the biexciton-exciton recombination cascade is complicated by the presence of an energy splitting between the intermediate excitonic levels, which severely degrades the quality of the entangled photon source. In this paper we present a novel, conceptually simple and straightforward proposal for restoring the entanglement of said source by applying a cascade of time-dependent operations on the emitted photons. This is in striking contrast with the techniques usually employed, that act on the quantum emitter itself in order to remove the fine structure splitting at its root. The feasibility of the implementation with current technology is discussed, and the robustness of the proposed compensation scheme with respect to imperfections of the experimental apparatus is evaluated via a series of Monte Carlo simulations.
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Affiliation(s)
- Simone Varo
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland.
| | - Gediminas Juska
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland
| | - Emanuele Pelucchi
- Tyndall National Institute, University College Cork, Dyke Parade, Cork, Republic of Ireland
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31
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Zhang S, Wu YK, Li C, Jiang N, Pu YF, Duan LM. Quantum-Memory-Enhanced Preparation of Nonlocal Graph States. Phys Rev Lett 2022; 128:080501. [PMID: 35275664 DOI: 10.1103/physrevlett.128.080501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Graph states are an important class of multipartite entangled states. Previous experimental generation of graph states and in particular the Greenberger-Horne-Zeilinger (GHZ) states in linear optics quantum information schemes is subjected to an exponential decay in efficiency versus the system size, which limits its large-scale applications in quantum networks. Here, we demonstrate an efficient scheme to prepare graph states with only a polynomial overhead using long-lived atomic quantum memories. We generate atom-photon entangled states in two atomic ensembles asynchronously, retrieve the stored atomic excitations only when both sides succeed, and further project them into a four-photon GHZ state. We measure the fidelity of this GHZ state and further demonstrate its applications in the violation of Bell-type inequalities and in quantum cryptography. Our work demonstrates the prospect of efficient generation of multipartite entangled states in large-scale distributed systems with applications in quantum information processing and metrology.
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Affiliation(s)
- Sheng Zhang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yu-Kai Wu
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Chang Li
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Nan Jiang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yun-Fei Pu
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
| | - Lu-Ming Duan
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, People's Republic of China
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32
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Wei ZY, Malz D, Cirac JI. Sequential Generation of Projected Entangled-Pair States. Phys Rev Lett 2022; 128:010607. [PMID: 35061477 DOI: 10.1103/physrevlett.128.010607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/30/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
We introduce plaquette projected entangled-pair states, a class of states in a lattice that can be generated by applying sequential unitaries acting on plaquettes of overlapping regions. They satisfy area-law entanglement, possess long-range correlations, and naturally generalize other relevant classes of tensor network states. We identify a subclass that can be more efficiently prepared in a radial fashion and that contains the family of isometric tensor network states [M. P. Zaletel and F. Pollmann, Phys. Rev. Lett. 124, 037201 (2020)PRLTAO0031-900710.1103/PhysRevLett.124.037201]. We also show how this subclass can be efficiently prepared using an array of photon sources.
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Affiliation(s)
- Zhi-Yuan Wei
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, D-80799 München, Germany
| | - Daniel Malz
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, D-80799 München, Germany
| | - J Ignacio Cirac
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Munich Center for Quantum Science and Technology (MCQST), Schellingstraße 4, D-80799 München, Germany
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33
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Uppu R, Midolo L, Zhou X, Carolan J, Lodahl P. Quantum-dot-based deterministic photon-emitter interfaces for scalable photonic quantum technology. Nat Nanotechnol 2021; 16:1308-1317. [PMID: 34663948 DOI: 10.1038/s41565-021-00965-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/21/2021] [Indexed: 05/26/2023]
Abstract
The scale-up of quantum hardware is fundamental to realize the full potential of quantum technology. Among a plethora of hardware platforms, photonics stands out: it provides a modular approach where the main challenges lie in the construction of high-quality building blocks and in the development of methods to interface the modules. The subsequent scale-up could exploit mature integrated photonics foundry technology to produce small-footprint quantum processors of immense complexity. Solid-state quantum emitters can realize a deterministic photon-emitter interface and enable key quantum photonic resources and functionalities, including on-demand single- and multi-photon-entanglement sources, as well as photon-photon nonlinear quantum gates. In this Review, we use the example of quantum dot devices to present the physics of deterministic photon-emitter interfaces, including the main photonic building blocks required to scale up, and discuss quantitative performance benchmarks. While our focus is on quantum dot devices, the presented methods also apply to other quantum-emitter platforms such as atoms, vacancy centres, molecules and superconducting qubits. We also identify applications within quantum communication and computing, presenting a route towards photonics with a genuine quantum advantage.
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Affiliation(s)
- Ravitej Uppu
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Physics & Astronomy, University of Iowa, Iowa City, IA, USA
| | - Leonardo Midolo
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Xiaoyan Zhou
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jacques Carolan
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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34
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Abudayyeh H, Mildner A, Liran D, Lubotzky B, Lüder L, Fleischer M, Rapaport R. Overcoming the Rate-Directionality Trade-off: A Room-Temperature Ultrabright Quantum Light Source. ACS Nano 2021; 15:17384-17391. [PMID: 34664938 DOI: 10.1021/acsnano.1c08591] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Deterministic GHz-rate single photon sources at room temperature would be essential components for various quantum applications. However, both the slow intrinsic decay rate and the omnidirectional emission of typical quantum emitters are two obstacles toward achieving such a goal which are hard to overcome simultaneously. Here, we solve this challenge by a hybrid approach using a complex monolithic photonic resonator constructed of a gold nanocone responsible for the rate enhancement, enclosed by a circular Bragg antenna for emission directionality. A repeatable process accurately binds quantum dots to the tip of the antenna-embedded nanocone. As a result, we achieve simultaneous 20-fold emission rate enhancement and record-high directionality leading to an increase in the observed brightness by a factor as large as 800 (130) into an NA = 0.22(0.5). We project that these miniaturized on-chip devices can reach photon rates approaching 1.4 × 108 photons/s and pure single photon rates of >107 photons/second after temporal purification processes, thus enabling ultrafast light-matter interfaces for quantum technologies at ambient conditions.
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Affiliation(s)
- Hamza Abudayyeh
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Annika Mildner
- Institute for Applied Physics and Center LISA+, University of Tuebingen, Auf der Morgenstelle 10, 72076, Tuebingen, Germany
| | - Dror Liran
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Boaz Lubotzky
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Lars Lüder
- Institute for Applied Physics and Center LISA+, University of Tuebingen, Auf der Morgenstelle 10, 72076, Tuebingen, Germany
| | - Monika Fleischer
- Institute for Applied Physics and Center LISA+, University of Tuebingen, Auf der Morgenstelle 10, 72076, Tuebingen, Germany
| | - Ronen Rapaport
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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35
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Smołka T, Posmyk K, Wasiluk M, Wyborski P, Gawełczyk M, Mrowiński P, Mikulicz M, Zielińska A, Reithmaier JP, Musiał A, Benyoucef M. Optical Quality of InAs/InP Quantum Dots on Distributed Bragg Reflector Emitting at 3rd Telecom Window Grown by Molecular Beam Epitaxy. Materials (Basel) 2021; 14:6270. [PMID: 34771794 PMCID: PMC8585182 DOI: 10.3390/ma14216270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/09/2021] [Accepted: 10/18/2021] [Indexed: 11/23/2022]
Abstract
We present an experimental study on the optical quality of InAs/InP quantum dots (QDs). Investigated structures have application relevance due to emission in the 3rd telecommunication window. The nanostructures are grown by ripening-assisted molecular beam epitaxy. This leads to their unique properties, i.e., low spatial density and in-plane shape symmetry. These are advantageous for non-classical light generation for quantum technologies applications. As a measure of the internal quantum efficiency, the discrepancy between calculated and experimentally determined photon extraction efficiency is used. The investigated nanostructures exhibit close to ideal emission efficiency proving their high structural quality. The thermal stability of emission is investigated by means of microphotoluminescence. This allows to determine the maximal operation temperature of the device and reveal the main emission quenching channels. Emission quenching is predominantly caused by the transition of holes and electrons to higher QD's levels. Additionally, these carriers could further leave the confinement potential via the dense ladder of QD states. Single QD emission is observed up to temperatures of about 100 K, comparable to the best results obtained for epitaxial QDs in this spectral range. The fundamental limit for the emission rate is the excitation radiative lifetime, which spreads from below 0.5 to almost 1.9 ns (GHz operation) without any clear spectral dispersion. Furthermore, carrier dynamics is also determined using time-correlated single-photon counting.
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Affiliation(s)
- Tristan Smołka
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Katarzyna Posmyk
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Maja Wasiluk
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Paweł Wyborski
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Michał Gawełczyk
- Department of Theoretical Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland;
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100 Toruń, Poland
| | - Paweł Mrowiński
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Monika Mikulicz
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Agata Zielińska
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Johann Peter Reithmaier
- Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), Institute of Nanostructure Technologies and Analytics (INA), University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany;
| | - Anna Musiał
- Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (T.S.); (K.P.); (M.W.); (P.W.); (P.M.); (M.M.); (A.Z.)
| | - Mohamed Benyoucef
- Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), Institute of Nanostructure Technologies and Analytics (INA), University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany;
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36
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García de Arquer FP, Talapin DV, Klimov VI, Arakawa Y, Bayer M, Sargent EH. Semiconductor quantum dots: Technological progress and future challenges. Science 2021; 373:373/6555/eaaz8541. [PMID: 34353926 DOI: 10.1126/science.aaz8541] [Citation(s) in RCA: 272] [Impact Index Per Article: 90.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In quantum-confined semiconductor nanostructures, electrons exhibit distinctive behavior compared with that in bulk solids. This enables the design of materials with tunable chemical, physical, electrical, and optical properties. Zero-dimensional semiconductor quantum dots (QDs) offer strong light absorption and bright narrowband emission across the visible and infrared wavelengths and have been engineered to exhibit optical gain and lasing. These properties are of interest for imaging, solar energy harvesting, displays, and communications. Here, we offer an overview of advances in the synthesis and understanding of QD nanomaterials, with a focus on colloidal QDs, and discuss their prospects in technologies such as displays and lighting, lasers, sensing, electronics, solar energy conversion, photocatalysis, and quantum information.
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Affiliation(s)
- F Pelayo García de Arquer
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada.,ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Barcelona 08860, Spain
| | - Dmitri V Talapin
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | - Victor I Klimov
- Chemistry Division, C-PCS, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | - Manfred Bayer
- Technische Universitat Dortmund, 44221 Dortmund, Germany
| | - Edward H Sargent
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada.
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37
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Abstract
Realization of electromagnetic energy confinement beyond the diffraction limit is crucial for high-performance on-chip devices. Herein we construct an array of nonradiative anapoles that originate from the destructive far-field interference of electric and toroidal dipole modes to achieve ultracompact and high-efficiency electromagnetic energy transfer without the coupler. We experimentally investigate the proposed metachain at mid-infrared frequencies and give the first near-field experimental evidence of anapole-based energy transfer, in which the spatial profile of the anapole mode is also unambiguously identified on the nanoscale. We further demonstrate that the metachain is intrinsically lossless and scalable at infrared wavelengths, realizing a 90° bending loss down to 0.32 dB at the optical communication wavelength. The present scheme bridges the gap between the energy confinement and the transfer of anapoles and opens a new gate for more compactly integrated photonic and energy devices, which can operate in a broad spectral range.
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Affiliation(s)
- Tiancheng Huang
- Institute of Engineering Thermophysics, School of Mechanical Engineering, Key Laboratory of Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Boxiang Wang
- Institute of Engineering Thermophysics, School of Mechanical Engineering, Key Laboratory of Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wenbin Zhang
- Institute of Engineering Thermophysics, School of Mechanical Engineering, Key Laboratory of Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Changying Zhao
- Institute of Engineering Thermophysics, School of Mechanical Engineering, Key Laboratory of Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
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38
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Ferguson RR, Dellantonio L, Balushi AA, Jansen K, Dür W, Muschik CA. Measurement-Based Variational Quantum Eigensolver. Phys Rev Lett 2021; 126:220501. [PMID: 34152185 DOI: 10.1103/physrevlett.126.220501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 06/13/2023]
Abstract
Variational quantum eigensolvers (VQEs) combine classical optimization with efficient cost function evaluations on quantum computers. We propose a new approach to VQEs using the principles of measurement-based quantum computation. This strategy uses entangled resource states and local measurements. We present two measurement-based VQE schemes. The first introduces a new approach for constructing variational families. The second provides a translation of circuit- to measurement-based schemes. Both schemes offer problem-specific advantages in terms of the required resources and coherence times.
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Affiliation(s)
- R R Ferguson
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo N2L 3G1, Canada
| | - L Dellantonio
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo N2L 3G1, Canada
| | - A Al Balushi
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo N2L 3G1, Canada
| | - K Jansen
- NIC, DESY Zeuthen, Platanenallee 6, 15738 Zeuthen, Germany
| | - W Dür
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21a, 6020 Innsbruck, Austria
| | - C A Muschik
- Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo N2L 3G1, Canada
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
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39
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Li JP, Gu X, Qin J, Wu D, You X, Wang H, Schneider C, Höfling S, Huo YH, Lu CY, Liu NL, Li L, Pan JW. Heralded Nondestructive Quantum Entangling Gate with Single-Photon Sources. Phys Rev Lett 2021; 126:140501. [PMID: 33891463 DOI: 10.1103/physrevlett.126.140501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Heralded entangling quantum gates are an essential element for the implementation of large-scale optical quantum computation. Yet, the experimental demonstration of genuine heralded entangling gates with free-flying output photons in linear optical system, was hindered by the intrinsically probabilistic source and double-pair emission in parametric down-conversion. Here, by using an on-demand single-photon source based on a semiconductor quantum dot embedded in a micropillar cavity, we demonstrate a heralded controlled-NOT (CNOT) operation between two single photons for the first time. To characterize the performance of the CNOT gate, we estimate its average quantum gate fidelity of (87.8±1.2)%. As an application, we generated event-ready Bell states with a fidelity of (83.4±2.4)%. Our results are an important step towards the development of photon-photon quantum logic gates.
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Affiliation(s)
- Jin-Peng 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
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Xuemei Gu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jian Qin
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Dian Wu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Xiang You
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Hui Wang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Christian Schneider
- Institute of Physics, Carl von Ossietzky University, 26129 Oldenburg, Germany
- Technische Physik, Physikalische Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Sven Höfling
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- Technische Physik, Physikalische Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Yong-Heng Huo
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Chao-Yang Lu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Nai-Le Liu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Li 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
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
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40
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Tomm N, Javadi A, Antoniadis NO, Najer D, Löbl MC, Korsch AR, Schott R, Valentin SR, Wieck AD, Ludwig A, Warburton RJ. A bright and fast source of coherent single photons. Nat Nanotechnol 2021; 16:399-403. [PMID: 33510454 DOI: 10.1038/s41565-020-00831-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/30/2020] [Indexed: 05/24/2023]
Abstract
A single-photon source is an enabling technology in device-independent quantum communication1, quantum simulation2,3, and linear optics-based4 and measurement-based quantum computing5. These applications employ many photons and place stringent requirements on the efficiency of single-photon creation. The scaling on efficiency is typically an exponential function of the number of photons. Schemes taking full advantage of quantum superpositions also depend sensitively on the coherence of the photons, that is, their indistinguishability6. Here, we report a single-photon source with a high end-to-end efficiency. We employ gated quantum dots in an open, tunable microcavity7. The gating provides control of the charge and electrical tuning of the emission frequency; the high-quality material ensures low noise; and the tunability of the microcavity compensates for the lack of control in quantum dot position and emission frequency. Transmission through the top mirror is the dominant escape route for photons from the microcavity, and this output is well matched to a single-mode fibre. With this design, we can create a single photon at the output of the final optical fibre on-demand with a probability of up to 57% and with an average two-photon interference visibility of 97.5%. Coherence persists in trains of thousands of photons with single-photon creation at a repetition rate of 1 GHz.
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Affiliation(s)
- Natasha Tomm
- Department of Physics, University of Basel, Basel, Switzerland
| | - Alisa Javadi
- Department of Physics, University of Basel, Basel, Switzerland.
| | | | - Daniel Najer
- Department of Physics, University of Basel, Basel, Switzerland
| | | | - Alexander Rolf Korsch
- Department of Physics, University of Basel, Basel, Switzerland
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Rüdiger Schott
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Sascha René Valentin
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Andreas Dirk Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
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41
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Krisnanda T, Ghosh S, Paterek T, Liew TCH. Creating and concentrating quantum resource states in noisy environments using a quantum neural network. Neural Netw 2021; 136:141-151. [PMID: 33486293 DOI: 10.1016/j.neunet.2021.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 12/30/2020] [Accepted: 01/05/2021] [Indexed: 11/19/2022]
Abstract
Quantum information processing tasks require exotic quantum states as a prerequisite. They are usually prepared with many different methods tailored to the specific resource state. Here we provide a versatile unified state preparation scheme based on a driven quantum network composed of randomly-coupled fermionic nodes. The output of such a system is then superposed with the help of linear mixing where weights and phases are trained in order to obtain desired output quantum states. We explicitly show that our method is robust and can be utilized to create almost perfect maximally entangled, NOON, W, cluster, and discorded states. Furthermore, the treatment includes energy decay in the system as well as dephasing and depolarization. Under these noisy conditions we show that the target states are achieved with high fidelity by tuning controllable parameters and providing sufficient strength to the driving of the quantum network. Finally, in very noisy systems, where noise is comparable to the driving strength, we show how to concentrate entanglement by mixing more states in a larger network.
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Affiliation(s)
- Tanjung Krisnanda
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore.
| | - Sanjib Ghosh
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore
| | - Tomasz Paterek
- Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, 80-308 Gdańsk, Poland
| | - Timothy C H Liew
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore; MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d'Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore.
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42
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Appel MH, Tiranov A, Javadi A, Löbl MC, Wang Y, Scholz S, Wieck AD, Ludwig A, Warburton RJ, Lodahl P. Coherent Spin-Photon Interface with Waveguide Induced Cycling Transitions. Phys Rev Lett 2021; 126:013602. [PMID: 33480775 DOI: 10.1103/physrevlett.126.013602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Solid-state quantum dots are promising candidates for efficient light-matter interfaces connecting internal spin degrees of freedom to the states of emitted photons. However, selection rules prevent the combination of efficient spin control and optical cyclicity in this platform. By utilizing a photonic crystal waveguide we here experimentally demonstrate optical cyclicity up to ≈15 through photonic state engineering while achieving high fidelity spin initialization and coherent optical spin control. These capabilities pave the way towards scalable multiphoton entanglement generation and on-chip spin-photon gates.
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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
| | - Alisa Javadi
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - Matthias C Löbl
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - Ying Wang
- 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, D-44801 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - 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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43
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Istrati D, Pilnyak Y, Loredo JC, Antón C, Somaschi N, Hilaire P, Ollivier H, Esmann M, Cohen L, Vidro L, Millet C, Lemaître A, Sagnes I, Harouri A, Lanco L, Senellart P, Eisenberg HS. Sequential generation of linear cluster states from a single photon emitter. Nat Commun 2020; 11:5501. [PMID: 33127924 PMCID: PMC7603328 DOI: 10.1038/s41467-020-19341-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 10/07/2020] [Indexed: 11/29/2022] Open
Abstract
Light states composed of multiple entangled photons—such as cluster states—are essential for developing and scaling-up quantum computing networks. Photonic cluster states can be obtained from single-photon sources and entangling gates, but so far this has only been done with probabilistic sources constrained to intrinsically low efficiencies, and an increasing hardware overhead. Here, we report the resource-efficient generation of polarization-encoded, individually-addressable photons in linear cluster states occupying a single spatial mode. We employ a single entangling-gate in a fiber loop configuration to sequentially entangle an ever-growing stream of photons originating from the currently most efficient single-photon source technology—a semiconductor quantum dot. With this apparatus, we demonstrate the generation of linear cluster states up to four photons in a single-mode fiber. The reported architecture can be programmed for linear-cluster states of any number of photons, that are required for photonic one-way quantum computing schemes. Generating photonic cluster states using a single non-heralded source and a single entangling gate would optimise scalability and reduce resource overhead. Here, the authors generate up to 4-photon cluster states using a quantum dot coupled to a fibre loop, with a fourfold generation rate of 10 Hz.
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Affiliation(s)
- D Istrati
- Racah Institute of Physics, Hebrew University of Jerusalem, 91904, Jerusalem, Israel.
| | - Y Pilnyak
- Racah Institute of Physics, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - J C Loredo
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - C Antón
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | | | - P Hilaire
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France.,Université Paris Diderot, Paris, France
| | - H Ollivier
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - M Esmann
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - L Cohen
- Racah Institute of Physics, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - L Vidro
- Racah Institute of Physics, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - C Millet
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - A Lemaître
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - I Sagnes
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - A Harouri
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - L Lanco
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France.,Université Paris Diderot, Paris, France
| | - P Senellart
- CNRS Centre for Nanoscience and Nanotechnology, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - H S Eisenberg
- Racah Institute of Physics, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
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44
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Besse JC, Reuer K, Collodo MC, Wulff A, Wernli L, Copetudo A, Malz D, Magnard P, Akin A, Gabureac M, Norris GJ, Cirac JI, Wallraff A, Eichler C. Realizing a deterministic source of multipartite-entangled photonic qubits. Nat Commun 2020; 11:4877. [PMID: 32985501 PMCID: PMC7522291 DOI: 10.1038/s41467-020-18635-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/04/2020] [Indexed: 11/23/2022] Open
Abstract
Sources of entangled electromagnetic radiation are a cornerstone in quantum information processing and offer unique opportunities for the study of quantum many-body physics in a controlled experimental setting. Generation of multi-mode entangled states of radiation with a large entanglement length, that is neither probabilistic nor restricted to generate specific types of states, remains challenging. Here, we demonstrate the fully deterministic generation of purely photonic entangled states such as the cluster, GHZ, and W state by sequentially emitting microwave photons from a controlled auxiliary system into a waveguide. We tomographically reconstruct the entire quantum many-body state for up to N = 4 photonic modes and infer the quantum state for even larger N from process tomography. We estimate that localizable entanglement persists over a distance of approximately ten photonic qubits.
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Affiliation(s)
| | - Kevin Reuer
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | | | - Arne Wulff
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Lucien Wernli
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Adrian Copetudo
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Daniel Malz
- Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, Garching, 85748, Germany
- Munich Center for Quantum Science and Technology, Schellingstrasse 4, München, 80799, Germany
| | - Paul Magnard
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Abdulkadir Akin
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Mihai Gabureac
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Graham J Norris
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
| | - J Ignacio Cirac
- Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, Garching, 85748, Germany
- Munich Center for Quantum Science and Technology, Schellingstrasse 4, München, 80799, Germany
| | - Andreas Wallraff
- Department of Physics, ETH Zurich, Zurich, CH-8093, Switzerland
- Quantum Center, ETH Zurich, Zurich, CH-8093, Switzerland
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45
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Zhai L, Löbl MC, Nguyen GN, Ritzmann J, Javadi A, Spinnler C, Wieck AD, Ludwig A, Warburton RJ. Low-noise GaAs quantum dots for quantum photonics. Nat Commun 2020; 11:4745. [PMID: 32958795 PMCID: PMC7506537 DOI: 10.1038/s41467-020-18625-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 09/03/2020] [Indexed: 11/18/2022] Open
Abstract
Quantum dots are both excellent single-photon sources and hosts for single spins. This combination enables the deterministic generation of Raman-photons—bandwidth-matched to an atomic quantum-memory—and the generation of photon cluster states, a resource in quantum communication and measurement-based quantum computing. GaAs quantum dots in AlGaAs can be matched in frequency to a rubidium-based photon memory, and have potentially improved electron spin coherence compared to the widely used InGaAs quantum dots. However, their charge stability and optical linewidths are typically much worse than for their InGaAs counterparts. Here, we embed GaAs quantum dots into an n-i-p-diode specially designed for low-temperature operation. We demonstrate ultra-low noise behaviour: charge control via Coulomb blockade, close-to lifetime-limited linewidths, and no blinking. We observe high-fidelity optical electron-spin initialisation and long electron-spin lifetimes for these quantum dots. Our work establishes a materials platform for low-noise quantum photonics close to the red part of the spectrum. GaAs quantum dots emitting at the near-red part of the spectrum usually suffers from excess charge-noise. With a careful design of a n-i-p-diode structure hosting GaAs quantum dots, the authors demonstrate ultralow-noise behaviour and high-fidelity spin initialisation close to rubidium wavelengths.
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Affiliation(s)
- Liang Zhai
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
| | - Matthias C Löbl
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Giang N Nguyen
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.,Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Julian Ritzmann
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Alisa Javadi
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Clemens Spinnler
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, DE-44780, Bochum, Germany
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
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46
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Azses D, Haenel R, Naveh Y, Raussendorf R, Sela E, Dalla Torre EG. Identification of Symmetry-Protected Topological States on Noisy Quantum Computers. Phys Rev Lett 2020; 125:120502. [PMID: 33016759 DOI: 10.1103/physrevlett.125.120502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 08/14/2020] [Indexed: 05/06/2023]
Abstract
Identifying topological properties is a major challenge because, by definition, topological states do not have a local order parameter. While a generic solution to this challenge is not available yet, a broad class of topological states, namely, symmetry-protected topological (SPT) states, can be identified by distinctive degeneracies in their entanglement spectrum. Here, we propose and realize two complementary protocols to probe these degeneracies based on, respectively, symmetry-resolved entanglement entropies and measurement-based computational algorithms. The two protocols link quantum information processing to the classification of SPT phases of matter. They invoke the creation of a cluster state and are implemented on an IBM quantum computer. The experimental findings are compared to noisy simulations, allowing us to study the stability of topological states to perturbations and noise.
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Affiliation(s)
- Daniel Azses
- Department of Physics, Bar-Ilan University, Ramat Gan 5290002, Israel
- Center for Quantum Entanglement Science and Technology, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Rafael Haenel
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Yehuda Naveh
- IBM Research-Haifa, Haifa University Campus, Mount Carmel, Haifa 31905, Israel
| | - Robert Raussendorf
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Eran Sela
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Emanuele G Dalla Torre
- Department of Physics, Bar-Ilan University, Ramat Gan 5290002, Israel
- Center for Quantum Entanglement Science and Technology, Bar-Ilan University, Ramat Gan 5290002, Israel
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47
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Abstract
The controlled generation of non-classical states of light is a challenging task at the heart of quantum optics. Aside from the mere spirit of science, the related research is strongly driven by applications in photonic quantum technologies, including the fields of quantum communication, quantum computation, and quantum metrology. In this context, the realization of integrated solid-state-based quantum-light sources is of particular interest, due to the prospects for scalability and device integration. This topical review focuses on solid-state quantum-light sources which are fabricated in a deterministic fashion. In this framework we cover quantum emitters represented by semiconductor quantum dots, colour centres in diamond, and defect-/strain-centres in two-dimensional materials. First, we introduce the topic of quantum-light sources and non-classical light generation for applications in photonic quantum technologies, motivating the need for the development of scalable device technologies to push the field towards real-world applications. In the second part, we summarize material systems hosting quantum emitters in the solid-state. The third part reviews deterministic fabrication techniques and comparatively discusses their advantages and disadvantages. The techniques are classified in bottom-up approaches, exploiting the site-controlled positioning of the quantum emitters themselves, and top-down approaches, allowing for the precise alignment of photonic microstructures to pre-selected quantum emitters. Special emphasis is put on the progress achieved in the development of in situ techniques, which significantly pushed the performance of quantum-light sources towards applications. Additionally, we discuss hybrid approaches, exploiting pick-and-place techniques or wafer-bonding. The fourth part presents state-of-the-art quantum-dot quantum-light sources based on the fabrication techniques presented in the previous sections, which feature engineered functionality and enhanced photon collection efficiency. The article closes by highlighting recent applications of deterministic solid-state-based quantum-light sources in the fields of quantum communication, quantum computing, and quantum metrology, and by discussing future perspectives in the field of solid-state quantum-light sources.
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Affiliation(s)
- Sven Rodt
- Institute of Solid-State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
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48
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Larsen MV, Guo X, Breum CR, Neergaard-Nielsen JS, Andersen UL. Deterministic generation of a two-dimensional cluster state. Science 2020; 366:369-372. [PMID: 31624213 DOI: 10.1126/science.aay4354] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/25/2019] [Indexed: 11/02/2022]
Abstract
Measurement-based quantum computation offers exponential computational speed-up through simple measurements on a large entangled cluster state. We propose and demonstrate a scalable scheme for the generation of photonic cluster states suitable for universal measurement-based quantum computation. We exploit temporal multiplexing of squeezed light modes, delay loops, and beam-splitter transformations to deterministically generate a cylindrical cluster state with a two-dimensional (2D) topological structure as required for universal quantum information processing. The generated state consists of more than 30,000 entangled modes arranged in a cylindrical lattice with 24 modes on the circumference, defining the input register, and a length of 1250 modes, defining the computation depth. Our demonstrated source of two-dimensional cluster states can be combined with quantum error correction to enable fault-tolerant quantum computation.
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Affiliation(s)
- Mikkel V Larsen
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark.
| | - Xueshi Guo
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Casper R Breum
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Jonas S Neergaard-Nielsen
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Ulrik L Andersen
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark.
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49
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Zhao TM, Chen Y, Yu Y, Li Q, Davanco M, Liu J. Advanced technologies for quantum photonic devices based on epitaxial quantum dots. Adv Quantum Technol 2020; 3:10.1002/qute.201900034. [PMID: 36452403 PMCID: PMC9706462 DOI: 10.1002/qute.201900034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Indexed: 05/12/2023]
Abstract
Quantum photonic devices are candidates for realizing practical quantum computers and networks. The development of integrated quantum photonic devices can greatly benefit from the ability to incorporate different types of materials with complementary, superior optical or electrical properties on a single chip. Semiconductor quantum dots (QDs) serve as a core element in the emerging modern photonic quantum technologies by allowing on-demand generation of single-photons and entangled photon pairs. During each excitation cycle, there is one and only one emitted photon or photon pair. QD photonic devices are on the verge of unfolding for advanced quantum technology applications. In this review, we focus on the latest significant progress of QD photonic devices. We first discuss advanced technologies in QD growth, with special attention to droplet epitaxy and site-controlled QDs. Then we overview the wavelength engineering of QDs via strain tuning and quantum frequency conversion techniques. We extend our discussion to advanced optical excitation techniques recently developed for achieving the desired emission properties of QDs. Finally, the advances in heterogeneous integration of active quantum light-emitting devices and passive integrated photonic circuits are reviewed, in the context of realizing scalable quantum information processing chips.
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Affiliation(s)
- Tian Ming Zhao
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Chen
- Institute for Integrative Nanosciences, Leibniz IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Qing Li
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marcelo Davanco
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jin Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
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50
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Bitton O, Gupta SN, Houben L, Kvapil M, Křápek V, Šikola T, Haran G. Vacuum Rabi splitting of a dark plasmonic cavity mode revealed by fast electrons. Nat Commun 2020; 11:487. [PMID: 31980624 PMCID: PMC6981195 DOI: 10.1038/s41467-020-14364-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/02/2020] [Indexed: 11/22/2022] Open
Abstract
Recent years have seen a growing interest in strong coupling between plasmons and excitons, as a way to generate new quantum optical testbeds and influence chemical dynamics and reactivity. Strong coupling to bright plasmonic modes has been achieved even with single quantum emitters. Dark plasmonic modes fare better in some applications due to longer lifetimes, but are difficult to probe as they are subradiant. Here, we apply electron energy loss (EEL) spectroscopy to demonstrate that a dark mode of an individual plasmonic bowtie can interact with a small number of quantum emitters, as evidenced by Rabi-split spectra. Coupling strengths of up to 85 meV place the bowtie-emitter devices at the onset of the strong coupling regime. Remarkably, the coupling occurs at the periphery of the bowtie gaps, even while the electron beam probes their center. Our findings pave the way for using EEL spectroscopy to study exciton-plasmon interactions involving non-emissive photonic modes. Dark plasmonic modes fare better in some applications due to longer lifetimes but, being subradiant, are difficult to probe. The authors apply electron energy loss spectroscopy to demonstrate that a dark mode of a plasmonic cavity can couple with a few quantum emitters to exhibit vacuum Rabi splitting.
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Affiliation(s)
- Ora Bitton
- Chemical Research Support Department, Weizmann Institute of Science, POB 26, 7610001, Rehovot, Israel
| | - Satyendra Nath Gupta
- Department of Chemical and Biological Physics, Weizmann Institute of Science, POB 26, 7610001, Rehovot, Israel
| | - Lothar Houben
- Chemical Research Support Department, Weizmann Institute of Science, POB 26, 7610001, Rehovot, Israel
| | - Michal Kvapil
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00, Brno, Czech Republic.,Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69, Brno, Czech Republic
| | - Vlastimil Křápek
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00, Brno, Czech Republic
| | - Tomáš Šikola
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00, Brno, Czech Republic.,Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69, Brno, Czech Republic
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, POB 26, 7610001, Rehovot, Israel.
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