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Artzi Y, Yishay Y, Fanciulli M, Jbara M, Blank A. Superconducting micro-resonators for electron spin resonance - the good, the bad, and the future. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 334:107102. [PMID: 34847488 DOI: 10.1016/j.jmr.2021.107102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/17/2021] [Accepted: 10/30/2021] [Indexed: 06/13/2023]
Abstract
The field of electron spin resonance (ESR) is in constant need of improving its capabilities. Among other things, this means having better resonators to reach improved spin sensitivity and enable larger microwave-power-to-microwave-magnetic-field conversion factors. Surface micro-resonators, made of small metallic patches on a dielectric substrate, provide very good absolute spin sensitivity and high conversion factors due to their very small mode volume. However, such resonators suffer from relatively low spin concentration sensitivity and a low-quality factor, a fact that offsets some of their significant potential advantages. The use of superconducting patches to replace the metallic layer seems a reasonable and straightforward solution to the quality factor issue, at least for measurements carried out at cryogenic temperatures. Nevertheless, superconducting materials, especially those that can operate at moderate cryogenic temperatures, are not easily incorporated into setups requiring high magnetic fields due to the electric current vortices generated in the latter's surface. This makes the transition from normal conducting materials to superconductors highly nontrivial. Here we present the design, fabrication, and testing results of surface micro-resonators made of yttrium barium copper oxide (YBCO), a superconducting material that operates also at high magnetic fields and makes it possible to pursue ESR at moderate cryogenic temperatures (up to ∼ 80 K). We show that with a unique experimental setup, these resonators can be made to operate well even at high fields of ∼ 1.2 T. Furthermore, we analyze the effect of current vortices on the ESR signal and the spins' coherence times. Finally, we provide a head-to-head comparison of YBCO vs copper resonators of the same dimensions, which clearly shows their pros and cons and directs us to future potential developments and improvements in this field.
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Affiliation(s)
- Yaron Artzi
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Yakir Yishay
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Marco Fanciulli
- Department of Materials Science, University of Milano - Bicocca, Italy
| | - Moamen Jbara
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
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2
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Sundar S, Sharath Chandra LS, Chattopadhyay MK, Roy SB. Evidence of multiband superconductivity in the β-phase Mo1-xRex alloys. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:045701. [PMID: 25563211 DOI: 10.1088/0953-8984/27/4/045701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a detailed study of the superconducting properties in the β-phase Mo(1-x)Re(x) (x = 0.25 and 0.4) solid solution alloys pursued through magnetization and heat capacity measurements. The temperature dependence of the upper critical field H(C2)(T) in these binary alloys shows a deviation from the prediction of the Werthamer-Helfand-Hohenberg (WHH) theory. The temperature dependence of superfluid density estimated from the variation of lower critical field H(C1) with temperature, cannot be explained within the framework of a single superconducting energy gap. The heat capacity also shows an anomalous feature in its temperature dependence. All these results can be reasonably explained by considering the existence of two superconducting energy gaps in these Mo(1-x)Re(x) alloys. Initial results of electronic structure calculations and resonant photoelectron spectroscopy measurements support this possibility and suggest that the Re-5d like states at the Fermi level may not intermix with the Mo-5p and 5s like states in the β-phase Mo(1-x)Re(x) alloys and contribute quite distinctly to the superconductivity of these alloys.
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Affiliation(s)
- Shyam Sundar
- Homi Bhabha National Institute at RRCAT, Indore, Madhya Pradesh 452 013, India
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3
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Putzke C, Walmsley P, Fletcher JD, Malone L, Vignolles D, Proust C, Badoux S, See P, Beere HE, Ritchie DA, Kasahara S, Mizukami Y, Shibauchi T, Matsuda Y, Carrington A. Anomalous critical fields in quantum critical superconductors. Nat Commun 2014; 5:5679. [PMID: 25477044 PMCID: PMC4268691 DOI: 10.1038/ncomms6679] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 10/28/2014] [Indexed: 11/22/2022] Open
Abstract
Fluctuations around an antiferromagnetic quantum critical point (QCP) are believed to lead to unconventional superconductivity and in some cases to high-temperature superconductivity. However, the exact mechanism by which this occurs remains poorly understood. The iron-pnictide superconductor BaFe2(As1−xPx)2 is perhaps the clearest example to date of a high-temperature quantum critical superconductor, and so it is a particularly suitable system to study how the quantum critical fluctuations affect the superconducting state. Here we show that the proximity of the QCP yields unexpected anomalies in the superconducting critical fields. We find that both the lower and upper critical fields do not follow the behaviour, predicted by conventional theory, resulting from the observed mass enhancement near the QCP. Our results imply that the energy of superconducting vortices is enhanced, possibly due to a microscopic mixing of antiferromagnetism and superconductivity, suggesting that a highly unusual vortex state is realized in quantum critical superconductors. Superconductivity in the iron pnictides is believed to be related to quantum critical fluctuations. Putzke et al. observe unexpected anomalies in the critical fields of BaFe2(As1−xPx)2 that emerge close to its magnetic critical point, which they argue is a generic feature of quantum critical superconductivity.
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Affiliation(s)
- C Putzke
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - P Walmsley
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - J D Fletcher
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK
| | - L Malone
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
| | - D Vignolles
- Laboratoire National des Champs Magnétiques Intenses (CNRS-INSA-UJF-UPS), 31400 Toulouse, France
| | - C Proust
- Laboratoire National des Champs Magnétiques Intenses (CNRS-INSA-UJF-UPS), 31400 Toulouse, France
| | - S Badoux
- Laboratoire National des Champs Magnétiques Intenses (CNRS-INSA-UJF-UPS), 31400 Toulouse, France
| | - P See
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK
| | - H E Beere
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - D A Ritchie
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - S Kasahara
- Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Y Mizukami
- 1] Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan [2] Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - T Shibauchi
- 1] Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan [2] Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - Y Matsuda
- Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - A Carrington
- H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
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4
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Grissonnanche G, Cyr-Choinière O, Laliberté F, René de Cotret S, Juneau-Fecteau A, Dufour-Beauséjour S, Delage MÈ, LeBoeuf D, Chang J, Ramshaw BJ, Bonn DA, Hardy WN, Liang R, Adachi S, Hussey NE, Vignolle B, Proust C, Sutherland M, Krämer S, Park JH, Graf D, Doiron-Leyraud N, Taillefer L. Direct measurement of the upper critical field in cuprate superconductors. Nat Commun 2014; 5:3280. [PMID: 24518054 PMCID: PMC3929805 DOI: 10.1038/ncomms4280] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 01/19/2014] [Indexed: 11/08/2022] Open
Abstract
In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+δ, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competition-associated with Fermi-surface reconstruction and charge-density-wave order-is a key limiting factor in the superconductivity of cuprates.
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Affiliation(s)
- G. Grissonnanche
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - O. Cyr-Choinière
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - F. Laliberté
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - S. René de Cotret
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - A. Juneau-Fecteau
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - S. Dufour-Beauséjour
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - M. -È. Delage
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - D. LeBoeuf
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
- Present address: Laboratoire National des Champs Magnétiques Intenses, Grenoble, France
| | - J. Chang
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
- Present address: École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - B. J. Ramshaw
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - D. A. Bonn
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
| | - W. N. Hardy
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
| | - R. Liang
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
| | - S. Adachi
- Superconductivity Research Laboratory, ISTEC, Yokohama, Kanagawa 223-0051, Japan
| | - N. E. Hussey
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
- Present address: High Field Magnet Laboratory, Radboud University Nijmegen, The Netherlands
| | - B. Vignolle
- Laboratoire National des Champs Magnétiques Intenses, Toulouse 31400, France
| | - C. Proust
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
- Laboratoire National des Champs Magnétiques Intenses, Toulouse 31400, France
| | - M. Sutherland
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
| | - S. Krämer
- Laboratoire National des Champs Magnétiques Intenses, Grenoble, France
| | - J. -H. Park
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - D. Graf
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - N. Doiron-Leyraud
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - Louis Taillefer
- Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
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Schneider T, Weyeneth S. Quantum superconductor-insulator transition: implications of BKT critical behavior. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:305701. [PMID: 23824507 DOI: 10.1088/0953-8984/25/30/305701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We explore the implications of Berezinskii-Kosterlitz-Thouless (BKT) critical behavior on the two-dimensional (2D) quantum superconductor-insulator (QSI) transition driven by the tuning parameter x. Concentrating on the sheet resistance R(x,T) BKT behavior implies: an explicit quantum scaling function for R(x,T) along the superconducting branch ending at the nonuniversal critical value Rc = R(xc); a BKT-transition line T(c)(x) [proportionality] (x - x(c))(zν[overline]), where z is the dynamic exponent and ν[overline] the exponent of the zero-temperature correlation length; independent estimates of zν[overline], z and ν[overline] from the x dependence of the nonuniversal parameters entering the BKT expression for the sheet resistance. To illustrate the potential and the implications of this scenario we analyze the data of Bollinger et al (2011 Nature 472 458) taken on gate voltage tuned epitaxial films of La2-xSrxCuO4 that are one unit cell in thickness. The resulting estimates, z ~/= 3.1 and ν[overline] ~/= 0.52, indicate a clean 2D-QSI critical point where hyperscaling, the proportionality between d/λ(2)(0) and Tc, and the correspondence between the quantum phase transitions in D dimensions and the classical ones in (D + z) dimensions are violated.
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Affiliation(s)
- T Schneider
- Physik-Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
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Ren C, Wang ZS, Luo HQ, Yang H, Shan L, Wen HH. Evidence for two energy gaps in superconducting Ba0.6K0.4Fe2As2 single crystals and the breakdown of the Uemura plot. PHYSICAL REVIEW LETTERS 2008; 101:257006. [PMID: 19113747 DOI: 10.1103/physrevlett.101.257006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Indexed: 05/27/2023]
Abstract
We report a detailed investigation on the lower critical field H{c1} of the superconducting Ba0.6K0.4Fe2As2 (122) single crystals. A pronounced kink is observed on the H{c1}(T) curve, which is attributed to the existence of two superconducting gaps. By fitting the data H{c1}(T) to the two-gap BCS model in the full temperature region, a small gap of Delta{a}(0)=2.0+/-0.3 meV and a large gap of Delta{b}(0)=8.9+/-0.4 meV are obtained. The in-plane penetration depth lambda{ab}(0) is estimated to be 105 nm corresponding to a rather large superfluid density, which points to the breakdown of the Uemura plot in 122 superconductors.
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Affiliation(s)
- Cong Ren
- National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China.
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7
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Kanigel A, Chatterjee U, Randeria M, Norman MR, Souma S, Shi M, Li ZZ, Raffy H, Campuzano JC. Protected nodes and the collapse of Fermi arcs in high-T{c} cuprate superconductors. PHYSICAL REVIEW LETTERS 2007; 99:157001. [PMID: 17995204 DOI: 10.1103/physrevlett.99.157001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Indexed: 05/25/2023]
Abstract
Angle resolved photoemission on underdoped Bi2Sr2CaCu2O8 reveals that the magnitude and d-wave anisotropy of the superconducting state energy gap are independent of temperature all the way up to T{c}. This lack of T variation of the entire k-dependent gap is in marked contrast to mean field theory. At T{c} the point nodes of the d-wave gap abruptly expand into finite length "Fermi arcs." This change occurs within the width of the resistive transition, and thus the Fermi arcs are not simply thermally broadened nodes but rather a unique signature of the pseudogap phase.
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Affiliation(s)
- A Kanigel
- Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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Franz M, Iyengar AP. Superfluid density of strongly underdoped cuprate superconductors from a four-dimensional XY model. PHYSICAL REVIEW LETTERS 2006; 96:047007. [PMID: 16486878 DOI: 10.1103/physrevlett.96.047007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2005] [Indexed: 05/06/2023]
Abstract
A new phenomenology is proposed for the superfluid density rhos of strongly underdoped cuprate superconductors based on recent data for ultraclean single crystals of YBa2Cu3O7-x. We show that the puzzling departure from Uemura scaling and the decline of the slope as the Tc=0 quantum critical point is approached can be understood in terms of the renormalization of quasiparticle effective charge by quantum fluctuations of the superconducting phase. We then employ a (3+1)-dimensional XY model to calculate, within particular approximations, the renormalization of rhos and its slope, explain the new phenomenology, and predict its eventual demise close to the quantum critical point.
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Affiliation(s)
- M Franz
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada V6T 1Z1
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9
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Zuev Y, Kim MS, Lemberger TR. Correlation between superfluid density and T(C) of underdoped YBa2Cu3O6+x near the superconductor-insulator transition. PHYSICAL REVIEW LETTERS 2005; 95:137002. [PMID: 16197167 DOI: 10.1103/physrevlett.95.137002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Indexed: 05/04/2023]
Abstract
We report measurements of the ab-plane superfluid density n(s) (magnetic penetration depth lambda) of heavily underdoped films of YBa2Cu3O6+x, with T(C)'s from 6 to 50 K. We find the characteristic length for vortex unbinding transition equal to the film thickness, suggesting strongly coupled CuO2 layers. At the lowest dopings, T(C) is as much as 5 times larger than the upper limit set by the 2D Kosterlitz-Thouless-Berezinskii transition temperature calculated for individual CuO2 bilayers. Our main finding is that T(C) is not proportional to n(s)(0); instead, we find T(C) proportional to ns(1/2.3+/-0.4). This conflicts with a popular point of view that quasi-2D thermal phase fluctuations determine the transition temperature.
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Affiliation(s)
- Yuri Zuev
- Department of Physics, Ohio State University, 191 Woodruff Avenue, Columbus, Ohio 43210, USA
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Herbut IF. Effective theory of high-temperature superconductors. PHYSICAL REVIEW LETTERS 2005; 94:237001. [PMID: 16090496 DOI: 10.1103/physrevlett.94.237001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Indexed: 05/03/2023]
Abstract
The field theory of a fluctuating d-wave superconductor is constructed and proposed as an effective description of superconducting cuprates at low energies. The theory is used to resolve a puzzle posed by recent experiments on superfluid density in severely underdoped YBa2(Cu3)O(6+x). In particular, the overall temperature dependence of the superfluid density at low dopings is argued to be described well by the strongly anisotropic weakly interacting Bose gas, and thus approximately linear in temperature with an almost doping-independent slope.
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Affiliation(s)
- Igor F Herbut
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
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