1
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Enhanced magnetic ordering by impurity Fe substitution on electron-doped superconductors Eu2-+Ce-Cu1-Fe O4+α-δ. Heliyon 2022; 8:e11501. [DOI: 10.1016/j.heliyon.2022.e11501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/23/2022] [Accepted: 11/02/2022] [Indexed: 11/14/2022] Open
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2
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Ultra-high critical current densities of superconducting YBa 2Cu 3O 7-δ thin films in the overdoped state. Sci Rep 2021; 11:8176. [PMID: 33854183 PMCID: PMC8047038 DOI: 10.1038/s41598-021-87639-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/24/2021] [Indexed: 02/02/2023] Open
Abstract
The functional properties of cuprates are strongly determined by the doping state and carrier density. We present an oxygen doping study of YBa2Cu3O7-δ (YBCO) thin films from underdoped to overdoped state, correlating the measured charge carrier density, [Formula: see text], the hole doping, p, and the critical current density, [Formula: see text]. Our results show experimental demonstration of strong increase of [Formula: see text] with [Formula: see text], up to Quantum Critical Point (QCP), due to an increase of the superconducting condensation energy. The ultra-high [Formula: see text] achieved, 90 MA cm-2 at 5 K corresponds to about a fifth of the depairing current, i.e. a value among the highest ever reported in YBCO films. The overdoped regime is confirmed by a sudden increase of [Formula: see text], associated to the reconstruction of the Fermi-surface at the QCP. Overdoping YBCO opens a promising route to extend the current carrying capabilities of rare-earth barium copper oxide (REBCO) coated conductors for applications.
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3
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Navarro H, Sirena M, Haberkorn N. Improving the Josephson energy in high-Tc superconducting junctions for ultra-fast electronics. NANOTECHNOLOGY 2020; 31:105701. [PMID: 31751967 DOI: 10.1088/1361-6528/ab59f7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the electrical transport of thin vertically-stacked Josephson tunnel junctions. The devices were fabricated using 16 nm thick GdBa2Cu3O7-δ electrodes and 1-4 nm SrTiO3 as an insulating barrier. The results show Josephson coupling for junctions with SrTiO3 barriers of 1 and 2 nm. Subtracting the residual current in the Fraunhofer patterns, energies of 3.1 mV and 5.7 mV at 12 K are obtained for STO barriers of 1 nm and 2 nm, respectively. The residual current may be related to the contribution of pinholes and thickness fluctuations in the STO barrier. These values are promising for reducing the influence of thermal noise and increasing the frequency operation rate in superconducting devices using high-temperature superconductors.
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Affiliation(s)
- H Navarro
- Instituto Balseiro, Universidad Nacional de Cuyo and Comisión Nacional de Energía Atómica, Av. Bustillo 9500, 8400 San Carlos de Bariloche, Argentina
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4
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Fernández-Rodríguez A, Alcalà J, Suñe J, Mestres N, Palau A. Multi-terminal Transistor-like Devices Based on Strongly Correlated Metallic Oxides for Neuromorphic Applications. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E281. [PMID: 31936337 PMCID: PMC7013969 DOI: 10.3390/ma13020281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/24/2019] [Accepted: 01/03/2020] [Indexed: 11/23/2022]
Abstract
Memristive devices are attracting a great attention for memory, logic, neural networks, and sensing applications due to their simple structure, high density integration, low-power consumption, and fast operation. In particular, multi-terminal structures controlled by active gates, able to process and manipulate information in parallel, would certainly provide novel concepts for neuromorphic systems. In this way, transistor-based synaptic devices may be designed, where the synaptic weight in the postsynaptic membrane is encoded in a source-drain channel and modified by presynaptic terminals (gates). In this work, we show the potential of reversible field-induced metal-insulator transition (MIT) in strongly correlated metallic oxides for the design of robust and flexible multi-terminal memristive transistor-like devices. We have studied different structures patterned on YBa2Cu3O7-δ films, which are able to display gate modulable non-volatile volume MIT, driven by field-induced oxygen diffusion within the system. The key advantage of these materials is the possibility to homogeneously tune the oxygen diffusion not only in a confined filament or interface, as observed in widely explored binary and complex oxides, but also in the whole material volume. Another important advantage of correlated oxides with respect to devices based on conducting filaments is the significant reduction of cycle-to-cycle and device-to-device variations. In this work, we show several device configurations in which the lateral conduction between a drain-source channel (synaptic weight) is effectively controlled by active gate-tunable volume resistance changes, thus providing the basis for the design of robust and flexible transistor-based artificial synapses.
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Affiliation(s)
- Alejandro Fernández-Rodríguez
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, Spain; (A.F.-R.); (J.A.); (N.M.)
| | - Jordi Alcalà
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, Spain; (A.F.-R.); (J.A.); (N.M.)
| | - Jordi Suñe
- Departament d’Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Narcis Mestres
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, Spain; (A.F.-R.); (J.A.); (N.M.)
| | - Anna Palau
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, Spain; (A.F.-R.); (J.A.); (N.M.)
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5
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Robinson NJ, Johnson PD, Rice TM, Tsvelik AM. Anomalies in the pseudogap phase of the cuprates: competing ground states and the role of umklapp scattering. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:126501. [PMID: 31300626 DOI: 10.1088/1361-6633/ab31ed] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Over the past two decades, advances in computational algorithms have revealed a curious property of the two-dimensional Hubbard model (and related theories) with hole doping: the presence of close-in-energy competing ground states that display very different physical properties. On the one hand, there is a complicated state exhibiting intertwined spin, charge, and pair density wave orders. We call this 'type A'. On the other hand, there is a uniform d-wave superconducting state that we denote as 'type B'. We advocate, with the support of both microscopic theoretical calculations and experimental data, dividing the high-temperature cuprate superconductors into two corresponding families, whose properties reflect either the type A or type B ground states at low temperatures. We review the anomalous properties of the pseudogap phase that led us to this picture, and present a modern perspective on the role that umklapp scattering plays in these phenomena in the type B materials. This reflects a consistent framework that has emerged over the last decade, in which Mott correlations at weak coupling drive the formation of the pseudogap. We discuss this development, recent theory and experiments, and open issues.
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Affiliation(s)
- Neil J Robinson
- Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Postbus 94485, 1098 XH Amsterdam, The Netherlands
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6
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Palau A, Fernandez-Rodriguez A, Gonzalez-Rosillo JC, Granados X, Coll M, Bozzo B, Ortega-Hernandez R, Suñé J, Mestres N, Obradors X, Puig T. Electrochemical Tuning of Metal Insulator Transition and Nonvolatile Resistive Switching in Superconducting Films. ACS APPLIED MATERIALS & INTERFACES 2018; 10:30522-30531. [PMID: 30109805 PMCID: PMC6348441 DOI: 10.1021/acsami.8b08042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
Modulation of carrier concentration in strongly correlated oxides offers the unique opportunity to induce different phases in the same material, which dramatically change their physical properties, providing novel concepts in oxide electronic devices with engineered functionalities. This work reports on the electric manipulation of the superconducting to insulator phase transition in YBa2Cu3O7-δ thin films by electrochemical oxygen doping. Both normal state resistance and the superconducting critical temperature can be reversibly manipulated in confined active volumes of the film by gate-tunable oxygen diffusion. Vertical and lateral oxygen mobility may be finely modulated, at the micro- and nano-scale, by tuning the applied bias voltage and operating temperature thus providing the basis for the design of homogeneous and flexible transistor-like devices with loss-less superconducting drain-source channels. We analyze the experimental results in light of a theoretical model, which incorporates thermally activated and electrically driven volume oxygen diffusion.
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Affiliation(s)
- Anna Palau
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | | | | | - Xavier Granados
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Mariona Coll
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Bernat Bozzo
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Rafael Ortega-Hernandez
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- Departament d’Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Jordi Suñé
- Departament d’Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Narcís Mestres
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Xavier Obradors
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Teresa Puig
- Institut de Ciència
de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
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7
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The effects of oxygen in spinel oxide Li 1+xTi 2-xO 4-δ thin films. Sci Rep 2018; 8:3995. [PMID: 29507404 PMCID: PMC5838103 DOI: 10.1038/s41598-018-22393-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/25/2018] [Indexed: 11/09/2022] Open
Abstract
The evolution from superconducting LiTi2O4-δ to insulating Li4Ti5O12 thin films has been studied by precisely tuning the oxygen pressure in the sample fabrication process. In superconducting LiTi2O4-δ films, with the increase of oxygen pressure, the oxygen vacancies are filled gradually and the c-axis lattice constant decreases. When the oxygen pressure increases to a certain critical value, the c-axis lattice constant becomes stable, which implies that the sample has been completely converted to Li4Ti5O12 phase. The two processes can be manifested by the angular bright-field images of the scanning transmission electron microscopy techniques. The transition temperature (T ch ) of magnetoresistance from the positive to the negative shows a nonmonotonic behavior, i.e. first decrease and then increase, with the increase of oxygen pressure. We suggest that the decrease Tch can be attributed to the suppressing of orbital-related state, and the inhomogeneous phase separated regions contribute positive MR and thereby lead to the reverse relation between Tch and oxygen pressure.
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8
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Bonino V, Agostino A, Prestipino C, Hernandez O, Fretto M, Mino L, Truccato M. Structural and functional modifications induced by X-ray nanopatterning in Bi-2212 single crystals. CrystEngComm 2018. [DOI: 10.1039/c8ce01183d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
X-ray nanopatterning induces both mosaicity increase and oxygen depletion in the high-Tc superconductor Bi2Sr2CaCu2O8+δ.
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Affiliation(s)
- Valentina Bonino
- Department of Physics
- Interdepartmental Centre NIS
- University of Torino
- I-10125 Torino
- Italy
| | - Angelo Agostino
- Department of Chemistry
- Interdepartmental Centre NIS and INSTM Centro di Riferimento
- University of Torino
- I-10125 Torino
- Italy
| | - Carmelo Prestipino
- University of Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226
- F-35000 Rennes
- France
| | - Olivier Hernandez
- University of Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226
- F-35000 Rennes
- France
| | - Matteo Fretto
- Nanofacility Piemonte INRiM (Istituto Nazionale di Ricerca Metrologica)
- Torino
- Italy
| | - Lorenzo Mino
- Department of Chemistry
- Interdepartmental Centre NIS and INSTM Centro di Riferimento
- University of Torino
- I-10125 Torino
- Italy
| | - Marco Truccato
- Department of Physics
- Interdepartmental Centre NIS
- University of Torino
- I-10125 Torino
- Italy
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9
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Geometrical vortex lattice pinning and melting in YBaCuO submicron bridges. Sci Rep 2016; 6:38677. [PMID: 28008911 PMCID: PMC5180090 DOI: 10.1038/srep38677] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/11/2016] [Indexed: 11/21/2022] Open
Abstract
Since the discovery of high-temperature superconductors (HTSs), most efforts of researchers have been focused on the fabrication of superconducting devices capable of immobilizing vortices, hence of operating at enhanced temperatures and magnetic fields. Recent findings that geometric restrictions may induce self-arresting hypervortices recovering the dissipation-free state at high fields and temperatures made superconducting strips a mainstream of superconductivity studies. Here we report on the geometrical melting of the vortex lattice in a wide YBCO submicron bridge preceded by magnetoresistance (MR) oscillations fingerprinting the underlying regular vortex structure. Combined magnetoresistance measurements and numerical simulations unambiguously relate the resistance oscillations to the penetration of vortex rows with intermediate geometrical pinning and uncover the details of geometrical melting. Our findings offer a reliable and reproducible pathway for controlling vortices in geometrically restricted nanodevices and introduce a novel technique of geometrical spectroscopy, inferring detailed information of the structure of the vortex system through a combined use of MR curves and large-scale simulations.
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10
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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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11
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Sonier JE, Brewer JH, Kiefl RF, Miller RI, Morris GD, Stronach CE, Gardner JS, Dunsiger SR, Bonn DA, Hardy WN, Liang R, Heffner RH. Anomalous weak magnetism in superconducting YBa2Cu3O6+x. Science 2001; 292:1692-5. [PMID: 11387468 DOI: 10.1126/science.1060844] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
For some time now, there has been considerable experimental and theoretical effort to understand the role of the normal-state "pseudogap" phase in underdoped high-temperature cuprate superconductors. Recent debate has centered on the question of whether the pseudogap is independent of superconductivity. We provide evidence from zero-field muon spin relaxation measurements in YBa2Cu3O6+x for the presence of small spontaneous static magnetic fields of electronic origin intimately related to the pseudogap transition. Our most significant finding is that, for optimal doping, these weak static magnetic fields appear well below the superconducting transition temperature. The two compositions measured suggest the existence of a quantum critical point somewhat above optimal doping.
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Affiliation(s)
- J E Sonier
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
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12
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Marchetti PA, Su ZB, Yu L. Metal-insulator crossover in superconducting cuprates in strong magnetic fields. PHYSICAL REVIEW LETTERS 2001; 86:3831-3834. [PMID: 11329335 DOI: 10.1103/physrevlett.86.3831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2000] [Indexed: 05/23/2023]
Abstract
The metal-insulator crossover of the in-plane resistivity upon temperature decrease, recently observed in several classes of cuprate superconductors, when a strong magnetic field suppresses the superconductivity, is explained using the U(1)xSU(2) Chern-Simons gauge field theory. The origin of this crossover is the same as that for a similar phenomenon observed in heavily underdoped cuprates without magnetic field. It is due to the interplay between the diffusive motion of the charge carriers and the "peculiar" localization effect due to short-range antiferromagnetic order. We also calculate the in-plane transverse magnetoresistance which is in fairly good agreement with available experimental data.
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Affiliation(s)
- P A Marchetti
- Dipartimento di Fisica "G. Galilei," INFN, I-35131 Padova, Italy
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13
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Dai P, Mook HA, Hayden SM, Aeppli G, Perring TG, Hunt RD, Dogan F. The magnetic excitation spectrum and thermodynamics of high-Tc superconductors. Science 1999; 284:1344-7. [PMID: 10334986 DOI: 10.1126/science.284.5418.1344] [Citation(s) in RCA: 244] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Inelastic neutron scattering was used to study the wave vector- and frequency-dependent magnetic fluctuations in single crystals of superconducting YBa2Cu3O6+x. The spectra contain several important features, including a gap in the superconducting state, a pseudogap in the normal state, and the much-discussed resonance peak. The appearance of the pseudogap determined from transport and nuclear resonance coincides with formation of the resonance in the magnetic excitations. The exchange energy associated with the resonance has the temperature and doping dependences as well as the magnitude to describe approximately the electronic specific heat near the superconducting transition temperature (Tc).
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Affiliation(s)
- P Dai
- Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6393, USA. H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK. NEC Research Institute, 4 Independence Way, Princeton, NJ 08540, USA. Rutherford Appl
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14
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Phillips JC. Filamentary microstructure and linear temperature dependence of normal state transport in optimized high temperature superconductors. Proc Natl Acad Sci U S A 1997; 94:12771-5. [PMID: 11038596 PMCID: PMC24213 DOI: 10.1073/pnas.94.24.12771] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A filamentary model of "metallic" conduction in layered high temperature superconductive cuprates explains the concurrence of normal state resistivities (Hall mobilities) linear in T (T-2) with optimized superconductivity. The model predicts the lowest temperature T0 for which linearity holds and it also predicts the maximum superconductive transition temperature Tc. The theory abandons the effective medium approximation that includes Fermi liquid as well as all other nonpercolative models in favor of countable smart basis states.
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Affiliation(s)
- J C Phillips
- Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974-0636, USA
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