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Tian Q, Izadi Vishkayi S, Bagheri Tagani M, Zhang L, Tian Y, Yin LJ, Zhang L, Qin Z. Two-Dimensional Artificial Ge Superlattice Confining in Electronic Kagome Lattice Potential Valleys. NANO LETTERS 2023; 23:9851-9857. [PMID: 37871176 DOI: 10.1021/acs.nanolett.3c02674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Constructing two-dimensional (2D) artificial superlattices based on single-atom and few-atom nanoclusters is of great interest for exploring exotic physics. Here we report the realization of two types of artificial germanium (Ge) superlattice self-confined by a 37 × 37 R25.3° superstructure of bismuth (Bi) induced electronic kagome lattice potential valleys. Scanning tunneling microscopy measurements demonstrate that Ge atoms prefer to be confined in the center of the Bi electronic kagome lattice, forming a single-atom superlattice at 120 K. In contrast, room temperature grown Ge atoms and clusters are confined in the sharing triangle corner and the center, respectively, of the kagome lattice potential valleys, forming an artificial honeycomb superlattice. First-principle calculations and Mulliken population analysis corroborate that our reported atomically thin Bi superstructure on Au(111) has a kagome surface potential valley with the center of the inner Bi hexagon and the space between the outer Bi hexagons being energetically favorable for trapping Ge atoms.
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Affiliation(s)
- Qiwei Tian
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Sahar Izadi Vishkayi
- School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran
| | - Meysam Bagheri Tagani
- Department of Physics, University of Guilan, P.O. Box 41335-1914, Rasht 32504550, Iran
| | - Li Zhang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Yuan Tian
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Long-Jing Yin
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Lijie Zhang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Zhihui Qin
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
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Hofmann EVS, Stock TJZ, Warschkow O, Conybeare R, Curson NJ, Schofield SR. Room Temperature Incorporation of Arsenic Atoms into the Germanium (001) Surface. Angew Chem Int Ed Engl 2023; 62:e202213982. [PMID: 36484458 PMCID: PMC10108107 DOI: 10.1002/anie.202213982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/29/2022] [Accepted: 12/09/2022] [Indexed: 12/13/2022]
Abstract
Germanium has emerged as an exceptionally promising material for spintronics and quantum information applications, with significant fundamental advantages over silicon. However, efforts to create atomic-scale devices using donor atoms as qubits have largely focused on phosphorus in silicon. Positioning phosphorus in silicon with atomic-scale precision requires a thermal incorporation anneal, but the low success rate for this step has been shown to be a fundamental limitation prohibiting the scale-up to large-scale devices. Here, we present a comprehensive study of arsine (AsH3 ) on the germanium (001) surface. We show that, unlike any previously studied dopant precursor on silicon or germanium, arsenic atoms fully incorporate into substitutional surface lattice sites at room temperature. Our results pave the way for the next generation of atomic-scale donor devices combining the superior electronic properties of germanium with the enhanced properties of arsine/germanium chemistry that promises scale-up to large numbers of deterministically placed qubits.
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Affiliation(s)
- Emily V S Hofmann
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Electronic and Electrical Engineering, University College London, London, WC1E 6BT, UK.,IHP Leibniz-Institut für Innovative Mikroelektronik, Im Technologiepark 25, 15236, Frankfurt (Oder), Germany
| | - Taylor J Z Stock
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Electronic and Electrical Engineering, University College London, London, WC1E 6BT, UK
| | - Oliver Warschkow
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
| | - Rebecca Conybeare
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - Neil J Curson
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Electronic and Electrical Engineering, University College London, London, WC1E 6BT, UK
| | - Steven R Schofield
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
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3
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The Local Exploration of Magnetic Field Effects in Semiconductors. CRYSTALS 2022. [DOI: 10.3390/cryst12040560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study reports on the local exploration of magnetic field effects in semiconductors, including silicon (Si), germanium (Ge), gallium arsenide (GaAs), and indium phosphide (InP) using the time differential perturbed angular correlation (TDPAC) technique. TDPAC measurements were carried out under external magnetic fields with strengths of 0.48 T and 2.1 T at room temperature, and 77 K following the implantation of 111In (111Cd) probes. Defects caused by ion implantation could be easily removed by thermal annealing at an appropriate temperature. The agreement between the measured Larmor frequencies and the theoretical values confirms that almost no intrinsic point defects are present in the semiconductors. At low temperatures, an electric interaction sets in. It stems from the electron capture after-effect. In the case of germanium and silicon, this effect is well visible. It is associated with a double charge state of the defect ion. No such effects arise in GaAs and InP where Cd contributes only a single electronic defect state. The Larmor frequencies correspond to the external magnetic field also at low temperatures.
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de Leon NP, Itoh KM, Kim D, Mehta KK, Northup TE, Paik H, Palmer BS, Samarth N, Sangtawesin S, Steuerman DW. Materials challenges and opportunities for quantum computing hardware. Science 2021; 372:372/6539/eabb2823. [PMID: 33859004 DOI: 10.1126/science.abb2823] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Quantum computing hardware technologies have advanced during the past two decades, with the goal of building systems that can solve problems that are intractable on classical computers. The ability to realize large-scale systems depends on major advances in materials science, materials engineering, and new fabrication techniques. We identify key materials challenges that currently limit progress in five quantum computing hardware platforms, propose how to tackle these problems, and discuss some new areas for exploration. Addressing these materials challenges will require scientists and engineers to work together to create new, interdisciplinary approaches beyond the current boundaries of the quantum computing field.
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Affiliation(s)
- Nathalie P de Leon
- Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, Yokohama 223-8522, Japan
| | - Dohun Kim
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea
| | - Karan K Mehta
- Department of Physics, Institute for Quantum Electronics, ETH Zürich, 8092 Zürich, Switzerland
| | - Tracy E Northup
- Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - Hanhee Paik
- IBM Quantum, IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA.
| | - B S Palmer
- Laboratory for Physical Sciences, University of Maryland, College Park, MD 20740, USA.,Quantum Materials Center, University of Maryland, College Park, MD 20742, USA
| | - N Samarth
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Sorawis Sangtawesin
- School of Physics and Center of Excellence in Advanced Functional Materials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - D W Steuerman
- Kavli Foundation, 5715 Mesmer Avenue, Los Angeles, CA 90230, USA
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5
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Hendrickx NW, Franke DP, Sammak A, Kouwenhoven M, Sabbagh D, Yeoh L, Li R, Tagliaferri MLV, Virgilio M, Capellini G, Scappucci G, Veldhorst M. Gate-controlled quantum dots and superconductivity in planar germanium. Nat Commun 2018; 9:2835. [PMID: 30026466 PMCID: PMC6053419 DOI: 10.1038/s41467-018-05299-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/20/2018] [Indexed: 11/09/2022] Open
Abstract
Superconductors and semiconductors are crucial platforms in the field of quantum computing. They can be combined to hybrids, bringing together physical properties that enable the discovery of new emergent phenomena and provide novel strategies for quantum control. The involved semiconductor materials, however, suffer from disorder, hyperfine interactions or lack of planar technology. Here we realise an approach that overcomes these issues altogether and integrate gate-defined quantum dots and superconductivity into germanium heterostructures. In our system, heavy holes with mobilities exceeding 500,000 cm2 (Vs)-1 are confined in shallow quantum wells that are directly contacted by annealed aluminium leads. We observe proximity-induced superconductivity in the quantum well and demonstrate electric gate-control of the supercurrent. Germanium therefore has great promise for fast and coherent quantum hardware and, being compatible with standard manufacturing, could become a leading material for quantum information processing.
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Affiliation(s)
- N W Hendrickx
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
| | - D P Franke
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - A Sammak
- QuTech and the Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK, Delft, The Netherlands
| | - M Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - D Sabbagh
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - L Yeoh
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - R Li
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M L V Tagliaferri
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M Virgilio
- Dipartimento di Fisica "E. Fermi", Università di Pisa, Largo Pontecorvo 3, 56127, Pisa, Italy
| | - G Capellini
- Dipartimento di Scienze, Università degli studi Roma Tre, Viale Marconi 446, 00146, Roma, Italy
- IHP, Im Technologiepark 25, 15236, Frankfurt (Oder), Germany
| | - G Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands
| | - M Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA, Delft, The Netherlands.
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Zhukov EA, Kirstein E, Kopteva NE, Heisterkamp F, Yugova IA, Korenev VL, Yakovlev DR, Pawlis A, Bayer M, Greilich A. Discretization of the total magnetic field by the nuclear spin bath in fluorine-doped ZnSe. Nat Commun 2018; 9:1941. [PMID: 29769536 PMCID: PMC5955946 DOI: 10.1038/s41467-018-04359-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/19/2018] [Indexed: 11/17/2022] Open
Abstract
The coherent spin dynamics of fluorine donor-bound electrons in ZnSe induced by pulsed optical excitation is studied in a perpendicular applied magnetic field. The Larmor precession frequency serves as a measure for the total magnetic field exerted onto the electron spins and, surprisingly, does not increase linearly with the applied field, but shows a step-like behavior with pronounced plateaus, given by multiples of the laser repetition rate. This discretization occurs by a feedback mechanism in which the electron spins polarize the nuclear spins, which in turn generate a local Overhauser field adjusting the total magnetic field accordingly. Varying the optical excitation power, we can control the plateaus, in agreement with our theoretical model. From this model, we trace the observed discretization to the optically induced Stark field, which causes the dynamic nuclear polarization. Understanding the electron and nuclear spin interactions is essential to the application of quantum information devices. Here the authors report a step-like electron Larmor frequency versus external magnetic field due to the discretization of the total magnetic field by the nuclear spin bath in ZnSe:F.
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Affiliation(s)
- E A Zhukov
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - E Kirstein
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - N E Kopteva
- Physical Faculty of St. Petersburg State University, 198504, St. Petersburg, Russia.,Spin Optics Laboratory, St. Petersburg State University, 198504, St. Petersburg, Russia
| | - F Heisterkamp
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Federal Institute for Occupational Safety and Health (BAuA), 44149, Dortmund, Germany
| | - I A Yugova
- Physical Faculty of St. Petersburg State University, 198504, St. Petersburg, Russia
| | - V L Korenev
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - A Pawlis
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - A Greilich
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.
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Sigillito AJ, Tyryshkin AM, Schenkel T, Houck AA, Lyon SA. All-electric control of donor nuclear spin qubits in silicon. NATURE NANOTECHNOLOGY 2017; 12:958-962. [PMID: 28805818 DOI: 10.1038/nnano.2017.154] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 07/03/2017] [Indexed: 06/07/2023]
Abstract
The electronic and nuclear spin degrees of freedom of donor impurities in silicon form ultra-coherent two-level systems that are potentially useful for applications in quantum information and are intrinsically compatible with industrial semiconductor processing. However, because of their smaller gyromagnetic ratios, nuclear spins are more difficult to manipulate than electron spins and are often considered too slow for quantum information processing. Moreover, although alternating current magnetic fields are the most natural choice to drive spin transitions and implement quantum gates, they are difficult to confine spatially to the level of a single donor, thus requiring alternative approaches. In recent years, schemes for all-electrical control of donor spin qubits have been proposed but no experimental demonstrations have been reported yet. Here, we demonstrate a scalable all-electric method for controlling neutral 31P and 75As donor nuclear spins in silicon. Using coplanar photonic bandgap resonators, we drive Rabi oscillations on nuclear spins exclusively using electric fields by employing the donor-bound electron as a quantum transducer, much in the spirit of recent works with single-molecule magnets. The electric field confinement leads to major advantages such as low power requirements, higher qubit densities and faster gate times. Additionally, this approach makes it possible to drive nuclear spin qubits either at their resonance frequency or at its first subharmonic, thus reducing device bandwidth requirements. Double quantum transitions can be driven as well, providing easy access to the full computational manifold of our system and making it convenient to implement nuclear spin-based qudits using 75As donors.
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Affiliation(s)
- Anthony J Sigillito
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Alexei M Tyryshkin
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Thomas Schenkel
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Andrew A Houck
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Stephen A Lyon
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
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Churbanov MF, Gavva VA, Bulanov AD, Abrosimov NV, Kozyrev EA, Andryushchenko IA, Lipskii VA, Adamchik SA, Troshin OY, Lashkov AY, Gusev AV. Production of germanium stable isotopes single crystals. CRYSTAL RESEARCH AND TECHNOLOGY 2017. [DOI: 10.1002/crat.201700026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mihail Fedorovich Churbanov
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Vladimir A. Gavva
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Andrey D. Bulanov
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | | | - Eugeniy A. Kozyrev
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Ivan A. Andryushchenko
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Victor A. Lipskii
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Sergey A. Adamchik
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Oleg Yu. Troshin
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Artem Yu. Lashkov
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
| | - Anatoly V. Gusev
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS; Tropinina str.,49 603951 Nizhnii Novgorod Russia
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10
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Strong confinement-induced engineering of the g factor and lifetime of conduction electron spins in Ge quantum wells. Nat Commun 2016; 7:13886. [PMID: 28000670 PMCID: PMC5187588 DOI: 10.1038/ncomms13886] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 11/09/2016] [Indexed: 11/08/2022] Open
Abstract
Control of electron spin coherence via external fields is fundamental in spintronics. Its implementation demands a host material that accommodates the desirable but contrasting requirements of spin robustness against relaxation mechanisms and sizeable coupling between spin and orbital motion of the carriers. Here, we focus on Ge, which is a prominent candidate for shuttling spin quantum bits into the mainstream Si electronics. So far, however, the intrinsic spin-dependent phenomena of free electrons in conventional Ge/Si heterojunctions have proved to be elusive because of epitaxy constraints and an unfavourable band alignment. We overcome these fundamental limitations by investigating a two-dimensional electron gas in quantum wells of pure Ge grown on Si. These epitaxial systems demonstrate exceptionally long spin lifetimes. In particular, by fine-tuning quantum confinement we demonstrate that the electron Landé g factor can be engineered in our CMOS-compatible architecture over a range previously inaccessible for Si spintronics.
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