1
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Benjamin SM. Intercalate Superconductivity and van der Waals Equation. ACS MATERIALS AU 2022; 2:436-439. [PMID: 35928829 PMCID: PMC9341279 DOI: 10.1021/acsmaterialsau.2c00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Superconductivity
in two single-element intercalated compounds
has been investigated with the van der Waals equation. For CuxTiSe2 and YBa2Cu3O6+x, the van der Waals term characterizing
the attractive energy per particle (i.e., electrons), aN/V, is calculated from concentration-dependent transition
temperature plots derived from experiment. It is shown that two times
the attractive energy per intercalant valence electron (2aNval/Vunit) is equal to the
energy gap predicted by BCS theory (Δ) for these superconductors.
This realization allows another way to estimate the energy gap of
superconducting intercalated insulators and semiconductors, this time,
directly from physical real-space properties of the superconductor
and the applied external pressure. The physical properties of importance
are shown to be the intercalant concentration, transition temperature,
and the number of intercalant valence electrons per unit cell volume.
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Affiliation(s)
- Shermane M. Benjamin
- The National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310, United States
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2
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Kim C, Bhoi D, Sur Y, Jeon BG, Wulferding D, Min BH, Kim J, Kim KH. Experimental signatures of nodeless multiband superconductivity in a [Formula: see text] single crystal. Sci Rep 2021; 11:13383. [PMID: 34183706 PMCID: PMC8239042 DOI: 10.1038/s41598-021-92709-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 05/20/2021] [Indexed: 11/20/2022] Open
Abstract
In order to understand the superconducting gap nature of a [Formula: see text] single crystal with [Formula: see text], in-plane thermal conductivity [Formula: see text], in-plane London penetration depth [Formula: see text], and the upper critical fields [Formula: see text] have been investigated. At zero magnetic field, it is found that no residual linear term [Formula: see text] exists and [Formula: see text] follows a power-law [Formula: see text] (T: temperature) with n = 2.66 at [Formula: see text], supporting nodeless superconductivity. Moreover, the magnetic-field dependence of [Formula: see text]/T clearly shows a shoulder-like feature at a low field region. The temperature dependent [Formula: see text] curves for both in-plane and out-of-plane field directions exhibit clear upward curvatures near [Formula: see text], consistent with the shape predicted by the two-band theory and the anisotropy ratio between the [Formula: see text](T) curves exhibits strong temperature-dependence. All these results coherently suggest that [Formula: see text] is a nodeless, multiband superconductor.
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Affiliation(s)
- Chanhee Kim
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
| | - Dilip Bhoi
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
- Present Address: The Institute for Solid State Physics (ISSP), The Institute for solid state Physics, The University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Yeahan Sur
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
| | - Byung-Gu Jeon
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
| | - Dirk Wulferding
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, 37673 South Korea
| | - Byeong Hun Min
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
| | - Jeehoon Kim
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673 South Korea
| | - Kee Hoon Kim
- Department of Physics and Astronomy, Center for Novel States of Complex Materials Research, Seoul National University, Seoul, 08826 Republic of Korea
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul, 08826 Republic of Korea
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3
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Takenaka T, Mizukami Y, Wilcox JA, Konczykowski M, Seiro S, Geibel C, Tokiwa Y, Kasahara Y, Putzke C, Matsuda Y, Carrington A, Shibauchi T. Full-Gap Superconductivity Robust against Disorder in Heavy-Fermion CeCu_{2}Si_{2}. PHYSICAL REVIEW LETTERS 2017; 119:077001. [PMID: 28949698 DOI: 10.1103/physrevlett.119.077001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Indexed: 06/07/2023]
Abstract
A key aspect of unconventional pairing by the antiferromagnetic spin-fluctuation mechanism is that the superconducting energy gap must have the opposite sign on different parts of the Fermi surface. Recent observations of non-nodal gap structure in the heavy-fermion superconductor CeCu_{2}Si_{2} were then very surprising, given that this material has long been considered a prototypical example of a superconductor where the Cooper pairing is magnetically mediated. Here we present a study of the effect of controlled point defects, introduced by electron irradiation, on the temperature-dependent magnetic penetration depth λ(T) in CeCu_{2}Si_{2}. We find that the fully gapped state is robust against disorder, demonstrating that low-energy bound states, expected for sign-changing gap structures, are not induced by nonmagnetic impurities. This provides bulk evidence for s_{++}-wave superconductivity without sign reversal.
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Affiliation(s)
- T Takenaka
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Y Mizukami
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - J A Wilcox
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, England
| | - M Konczykowski
- Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay, F-91128 Palaiseau, France
| | - S Seiro
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Institute for Solid State Physics, IFW-Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - C Geibel
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Y Tokiwa
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
- Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg University, 86159 Augsburg, Germany
| | - Y Kasahara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - C Putzke
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, England
| | - Y Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - A Carrington
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, England
| | - T Shibauchi
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
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4
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Erdenemunkh U, Koopman B, Fu L, Chatterjee K, Wise WD, Gu GD, Hudson EW, Boyer MC. Suppression of Superfluid Density and the Pseudogap State in the Cuprates by Impurities. PHYSICAL REVIEW LETTERS 2016; 117:257003. [PMID: 28036192 DOI: 10.1103/physrevlett.117.257003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Indexed: 06/06/2023]
Abstract
We use scanning tunneling microscopy (STM) to study magnetic Fe impurities intentionally doped into the high-temperature superconductor Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}. Our spectroscopic measurements reveal that Fe impurities introduce low-lying resonances in the density of states at Ω_{1}≈4 meV and Ω_{2}≈15 meV, allowing us to determine that, despite having a large magnetic moment, potential scattering of quasiparticles by Fe impurities dominates magnetic scattering. In addition, using high-resolution spatial characterizations of the local density of states near and away from Fe impurities, we detail the spatial extent of impurity-affected regions as well as provide a local view of impurity-induced effects on the superconducting and pseudogap states. Our studies of Fe impurities, when combined with a reinterpretation of earlier STM work in the context of a two-gap scenario, allow us to present a unified view of the atomic-scale effects of elemental impurities on the pseudogap and superconducting states in hole-doped cuprates; this may help resolve a previously assumed dichotomy between the effects of magnetic and nonmagnetic impurities in these materials.
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Affiliation(s)
- Unurbat Erdenemunkh
- Department of Physics, Clark University, Worcester, Massachusetts 01610, USA
| | - Brian Koopman
- Department of Physics, Clark University, Worcester, Massachusetts 01610, USA
| | - Ling Fu
- Department of Physics, Clark University, Worcester, Massachusetts 01610, USA
| | - Kamalesh Chatterjee
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - W D Wise
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - E W Hudson
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Pennsylvania State University, State College, Pennsylvania 16802, USA
| | - Michael C Boyer
- Department of Physics, Clark University, Worcester, Massachusetts 01610, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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5
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Ramshaw BJ, Sebastian SE, McDonald RD, Day J, Tan BS, Zhu Z, Betts JB, Liang R, Bonn DA, Hardy WN, Harrison N. Quasiparticle mass enhancement approaching optimal doping in a high-Tc superconductor. Science 2015; 348:317-20. [DOI: 10.1126/science.aaa4990] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/16/2015] [Indexed: 11/02/2022]
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6
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Mizukami Y, Konczykowski M, Kawamoto Y, Kurata S, Kasahara S, Hashimoto K, Mishra V, Kreisel A, Wang Y, Hirschfeld PJ, Matsuda Y, Shibauchi T. Disorder-induced topological change of the superconducting gap structure in iron pnictides. Nat Commun 2014; 5:5657. [PMID: 25430419 DOI: 10.1038/ncomms6657] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 10/24/2014] [Indexed: 11/09/2022] Open
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7
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Hashimoto K, Mizukami Y, Katsumata R, Shishido H, Yamashita M, Ikeda H, Matsuda Y, Schlueter JA, Fletcher JD, Carrington A, Gnida D, Kaczorowski D, Shibauchi T. Anomalous superfluid density in quantum critical superconductors. Proc Natl Acad Sci U S A 2013; 110:3293-7. [PMID: 23404698 PMCID: PMC3587240 DOI: 10.1073/pnas.1221976110] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
When a second-order magnetic phase transition is tuned to zero temperature by a nonthermal parameter, quantum fluctuations are critically enhanced, often leading to the emergence of unconventional superconductivity. In these "quantum critical" superconductors it has been widely reported that the normal-state properties above the superconducting transition temperature T(c) often exhibit anomalous non-Fermi liquid behaviors and enhanced electron correlations. However, the effect of these strong critical fluctuations on the superconducting condensate below T(c) is less well established. Here we report measurements of the magnetic penetration depth in heavy-fermion, iron-pnictide, and organic superconductors located close to antiferromagnetic quantum critical points, showing that the superfluid density in these nodal superconductors universally exhibits, unlike the expected T-linear dependence, an anomalous 3/2 power-law temperature dependence over a wide temperature range. We propose that this noninteger power law can be explained if a strong renormalization of effective Fermi velocity due to quantum fluctuations occurs only for momenta k close to the nodes in the superconducting energy gap Δ(k). We suggest that such "nodal criticality" may have an impact on low-energy properties of quantum critical superconductors.
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Affiliation(s)
| | - Yuta Mizukami
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Ryo Katsumata
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | | | | | - Hiroaki Ikeda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Yuji Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - John A. Schlueter
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439
| | - Jonathan D. Fletcher
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, United Kingdom; and
| | - Antony Carrington
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, United Kingdom; and
| | - Daniel Gnida
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław, Poland
| | - Dariusz Kaczorowski
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław, Poland
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8
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Noat Y, Cren T, Dubost V, Lange S, Debontridder F, Toulemonde P, Marcus J, Sulpice A, Sacks W, Roditchev D. Disorder effects in pnictides: a tunneling spectroscopy study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:465701. [PMID: 21403373 DOI: 10.1088/0953-8984/22/46/465701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present the synthesis and the tunneling spectroscopy study of superconducting FeSe(0.5)Te(0.5) (T(c) = 14 K), SmFeAsO(0.85) (T(c) = 54 K) and SmFeAsO(0.9)F(0.1) (T(c) = 45 K). The samples were characterized by Rietveld refinement of x-ray diffraction patterns and transport as well as temperature-dependent magnetic measurements. Tunneling experiments on FeSe(0.5)Te(0.5) revealed a single superconducting gap ∼ 1 meV in BCS-like tunneling conductance spectra. In SmFeAsO(0.85) and SmFeAsO(0.9)F(0.1), however, more complex spectra were observed, characterized by two gap-like structures at ∼ 4 and ∼ 10 meV. These spectra are qualitatively understood assuming a two-band superconductor with a 's ±' order parameter. We show that, depending on the sign relation between the pairing amplitudes in the two bands, the interband quasiparticle scattering has a crucial effect on the shape of the tunneling spectra. On the other hand, single-gap spectra found in FeSe(0.5)Te(0.5) are more compatible with a disorder-induced 's '-wave gap, due to the Se-Te substitution.
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Affiliation(s)
- Y Noat
- Institut des Nanosciences de Paris, CNRS UMR 7588, Université Pierre et Marie Curie Paris 6, Paris, France.
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9
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Hashimoto K, Shibauchi T, Kasahara S, Ikada K, Tonegawa S, Kato T, Okazaki R, van der Beek CJ, Konczykowski M, Takeya H, Hirata K, Terashima T, Matsuda Y. Microwave surface-impedance measurements of the magnetic penetration depth in single crystal Ba1-xKxFe2As2 superconductors: evidence for a disorder-dependent superfluid density. PHYSICAL REVIEW LETTERS 2009; 102:207001. [PMID: 19519062 DOI: 10.1103/physrevlett.102.207001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Indexed: 05/27/2023]
Abstract
We report high-sensitivity microwave measurements of the in-plane penetration depth lambda_{ab} and quasiparticle scattering rate 1/tau in several single crystals of the hole-doped Fe-based superconductor Ba(1-x)K(x)Fe(2)As(2) (x approximately 0.55). While a power-law temperature dependence of lambda_{ab} with a power approximately 2 is found in crystals with large 1/tau, we observe an exponential temperature dependence of the superfluid density consistent with the existence of fully opened two gaps in the cleanest crystal we studied. The difference may be a consequence of different levels of disorder inherent in the crystals. We also find a linear relation between the low-temperature scattering rate and the density of quasiparticles, which shows a clear contrast to the case of d-wave cuprate superconductors with nodes in the gap. These results demonstrate intrinsically nodeless order parameters in the Fe arsenides.
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Affiliation(s)
- K Hashimoto
- Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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10
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Broun DM, Huttema WA, Turner PJ, Ozcan S, Morgan B, Liang R, Hardy WN, Bonn DA. Superfluid density in a highly underdoped YBa_{2}Cu_{3}O_{6+y} superconductor. PHYSICAL REVIEW LETTERS 2007; 99:237003. [PMID: 18233402 DOI: 10.1103/physrevlett.99.237003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Indexed: 05/25/2023]
Abstract
The superfluid density rho_{s}(T) identical with1/lambda;{2}(T) has been measured at 2.64 GHz in highly underdoped YBa_{2}Cu_{3}O_{6+y}, at 37 dopings with T_{c} between 3 and 17 K. Within limits set by the transition width DeltaT_{c} approximately 0.4 K, rho_{s}(T) shows no evidence of critical fluctuations as T-->T_{c}, with a mean-field-like transition and no indication of vortex unbinding. Instead, we propose that rho_{s} displays the behavior expected for a quantum phase transition in the (3+1)-dimensional XY universality class, with rho_{s0} proportional, variant(p-p_{c}), T_{c} proportional, variant(p-p_{c});{1/2}, and rho_{s}(T) proportional, variant(T_{c}-T);{1} as T-->T_{c}.
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Affiliation(s)
- D M Broun
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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11
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Ouazi S, Bobroff J, Alloul H, Le Tacon M, Blanchard N, Collin G, Julien MH, Horvatić M, Berthier C. Impurity-induced local magnetism and density of states in the superconducting state of YBa2Cu3O7. PHYSICAL REVIEW LETTERS 2006; 96:127005. [PMID: 16605949 DOI: 10.1103/physrevlett.96.127005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2005] [Indexed: 05/08/2023]
Abstract
17O NMR is used to probe the local influence of nonmagnetic Zn and magnetic Ni impurities in the superconducting state of optimally doped high TC YBa2Cu3O7. Zn and Ni induce a staggered paramagnetic polarization, similar to that evidenced above TC, with a typical extension xi=3 cell units for Zn and xi>or=3 for Ni. In addition, Zn is observed to induce a local density of states near the Fermi energy in its neighborhood, which also decays over about 3 cell units. Its magnitude decreases sharply with increasing temperature. This allows direct comparison with the STM observations done in BiSCCO.
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Affiliation(s)
- S Ouazi
- Laboratoire de Physique des Solides, UMR8502, Université Paris XI, 91405 Orsay, France
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12
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Williams GA. Vortex fluctuations in the critical Casimir effect of superfluid and superconducting films. PHYSICAL REVIEW LETTERS 2004; 92:197003. [PMID: 15169438 DOI: 10.1103/physrevlett.92.197003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Indexed: 05/24/2023]
Abstract
Vortex-loop renormalization techniques are used to calculate the magnitude of the critical Casimir forces in superfluid films. The force is found to become appreciable when the size of the thermal vortex loops is comparable to the film thickness, and the results for T<T(c) are found to match very well with perturbative renormalization theories that have been carried out only for T>T(c). When applied to a high-T(c) superconducting film connected to a bulk sample, the Casimir force causes a voltage difference to appear between the film and the bulk, and estimates show that this may be readily measurable.
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Affiliation(s)
- Gary A Williams
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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13
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Joglekar YN, Castro Neto AH, Balatsky AV. Nodal Cooper-pair stabilized phase dynamics in granular d-wave superconductors. PHYSICAL REVIEW LETTERS 2004; 92:037004. [PMID: 14753898 DOI: 10.1103/physrevlett.92.037004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2003] [Indexed: 05/24/2023]
Abstract
Scanning tunneling microscope measurements on single crystals of Bi2Sr2CaCu2O8+x materials have shown that the d-wave superconductivity in cuprates has nanoscale inhomogeneities and is still robust in spite of their presence. We study the dynamics of Josephson coupling between such granular d-wave superconductors, focusing on the effect of nodal Cooper pairs and disorder. We find that the nodal Cooper pairs give rise to a power-law Josephson coupling which leads to the stabilization of the superconducting phase. Our findings suggest that the d-wave superconductivity in an array of grains is unexpectedly robust against a disordering transition, as observed in the experiments. Furthermore, we predict the existence of a planar Josephson-plasmon mode with characteristic frequency that decreases with temperature.
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Affiliation(s)
- Yogesh N Joglekar
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
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14
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Skinta JA, Lemberger TR, Greibe T, Naito M. Evidence for a nodeless gap from the superfluid density of optimally doped Pr(1.855)Ce(0.145)CuO(4-y) films. PHYSICAL REVIEW LETTERS 2002; 88:207003. [PMID: 12005592 DOI: 10.1103/physrevlett.88.207003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2001] [Indexed: 05/23/2023]
Abstract
We present measurements of the ab-plane magnetic penetration depth, lambda(T), in five optimally doped Pr(1.855)Ce(0.145)CuO(4-y) films for 1.6 K< or =T < or =T(c) approximately 24 K. Low resistivities, high superfluid densities n(s)(T) proportional, variant lambda(-2)(T), high T(c)'s, and small transition widths are reproducible and indicative of excellent film quality. For all five films, lambda(-2)(T)/lambda(-2)(0) at low T is well fitted by an exponential temperature dependence with a gap, Delta(min), of 0.85k(B)T(c). This behavior is consistent with a nodeless gap and is incompatible with d-wave superconductivity.
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Affiliation(s)
- John A Skinta
- Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106, USA
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15
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Ormeno RJ, Sibley A, Gough CE, Sebastian S, Fisher IR. Microwave conductivity and penetration depth in the heavy fermion superconductor CeCoIn5. PHYSICAL REVIEW LETTERS 2002; 88:047005. [PMID: 11801159 DOI: 10.1103/physrevlett.88.047005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2001] [Indexed: 05/23/2023]
Abstract
The electrodynamic properties of the quasi-two-dimensional heavy fermion superconductor CeCoIn5 have been investigated by microwave surface impedance measurements over a wide range of microwave frequencies and temperatures. We derive a value penetration depth lambda(0) approximately 190 nm, with a strong linear term in the temperature dependence of lambda(T) below T(c)/3, consistent with a superconducting gap with line nodes. The real part of the conductivity displays a broad peak at low temperatures consistent with a decreased scattering rate of almost 2 orders of magnitude below T(c). CeCoIn5 has remarkably similar properties to those of the high-T(c) cuprates.
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Affiliation(s)
- Rodrigo J Ormeno
- School of Physics and Astronomy, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
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16
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Hudson EW, Lang KM, Madhavan V, Pan SH, Eisaki H, Uchida S, Davis JC. Interplay of magnetism and high-Tc superconductivity at individual Ni impurity atoms in Bi2Sr2CaCu2O8+delta. Nature 2001; 411:920-4. [PMID: 11418850 DOI: 10.1038/35082019] [Citation(s) in RCA: 289] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Magnetic interactions and magnetic impurities are destructive to superconductivity in conventional superconductors. By contrast, in some unconventional macroscopic quantum systems (such as superfluid 3He and superconducting UGe2), the superconductivity (or superfluidity) is actually mediated by magnetic interactions. A magnetic mechanism has also been proposed for high-temperature superconductivity. Within this context, the fact that magnetic Ni impurity atoms have a weaker effect on superconductivity than non-magnetic Zn atoms in the high-Tc superconductors has been put forward as evidence supporting a magnetic mechanism. Here we use scanning tunnelling microscopy to determine directly the influence of individual Ni atoms on the local electronic structure of Bi2Sr2CaCu2O8+delta. At each Ni site we observe two d-wave impurity states of apparently opposite spin polarization, whose existence indicates that Ni retains a magnetic moment in the superconducting state. However, analysis of the impurity-state energies shows that quasiparticle scattering at Ni is predominantly non-magnetic. Furthermore, we show that the superconducting energy gap and correlations are unimpaired at Ni. This is in strong contrast to the effects of non-magnetic Zn impurities, which locally destroy superconductivity. These results are consistent with predictions for impurity atom phenomena derived from a magnetic mechanism.
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Affiliation(s)
- E W Hudson
- Department of Physics, University of California, Berkeley, California 94720, USA
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17
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Salluzzo M, Palomba F, Pica G, Andreone A, Maggio-Aprile I, Fischer O, Cantoni C, Norton DP. Role of Nd/Ba disorder on the penetration depth of Nd(1+x)Ba(2-x)Cu(3)O(7-delta) thin films. PHYSICAL REVIEW LETTERS 2000; 85:1116-1119. [PMID: 10991488 DOI: 10.1103/physrevlett.85.1116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/1999] [Indexed: 05/23/2023]
Abstract
We report on a study on the effect of Nd/Ba disorder on the ab-plane penetration depth of epitaxial Nd(1+x)Ba(2-x)Cu(3)O(7-delta) thin films. While in stoichiometric samples lambda(T) at low temperature is linear, Nd-rich films exhibit a quadratic law. For low Nd excess (x<0.04), a satisfying fit is obtained using the "dirty" d-wave model assuming that Nd ions at Ba sites act as strong scattering centers. At high x (x>0.15) the data are explained if Nd/Ba disorder becomes less effective as a source of scattering. The effect of localization has been discussed to account for the experimental results.
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Affiliation(s)
- M Salluzzo
- INFM and Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, I-80125 Napoli, Italy
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Feng DL, Lu DH, Shen KM, Kim C, Eisaki H, Damascelli A, Yoshizaki R, Shimoyama J, Kishio K, Gu GD, Oh S, Andrus A, O'Donnell J, Eckstein JN, Shen Z. Signature of superfluid density in the single-particle excitation spectrum of Bi(2)Sr(2)CaCu(2)O(8+delta). Science 2000; 289:277-81. [PMID: 10894771 DOI: 10.1126/science.289.5477.277] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report that the doping and temperature dependence of photoemission spectra near the Brillouin zone boundary of Bi(2)Sr(2)CaCu(2)O(8+delta)exhibit unexpected sensitivity to the superfluid density. In the superconducting state, the photoemission peak intensity as a function of doping scales with the superfluid density and the condensation energy. As a function of temperature, the peak intensity shows an abrupt behavior near the superconducting phase transition temperature where phase coherence sets in, rather than near the temperature where the gap opens. This anomalous manifestation of collective effects in single-particle spectroscopy raises important questions concerning the mechanism of high-temperature superconductivity.
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Affiliation(s)
- DL Feng
- Department of Physics, Applied Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94305, USA. Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305, Japan. Department of Applied Chem
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Tsuei CC, Kirtley JR. Phase-sensitive evidence for d-wave pairing symmetry in electron-doped cuprate superconductors. PHYSICAL REVIEW LETTERS 2000; 85:182-185. [PMID: 10991189 DOI: 10.1103/physrevlett.85.182] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2000] [Indexed: 05/23/2023]
Abstract
We present phase-sensitive evidence that the electron-doped cuprates Nd(1.85)Ce(0.15)CuO(4-y) (NCCO) and Pr(1.85)Ce(0.15)CuO(4-y) (PCCO) have d-wave pairing symmetry. This evidence was obtained by observing the half-flux quantum effect, using a scanning SQUID microscope, in c-axis-oriented films of NCCO or PCCO epitaxially grown on tricrystal [100] SrTiO3 substrates designed to be frustrated for a d(x(2)-y(2)) order parameter. Samples with two other configurations, designed to be unfrustrated for a d-wave superconductor, do not show the half-flux quantum effect.
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Affiliation(s)
- CC Tsuei
- IBM T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598, USA
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Imaging the effects of individual zinc impurity atoms on superconductivity in Bi2Sr2CaCu2O8+delta. Nature 2000; 403:746-50. [PMID: 10693798 DOI: 10.1038/35001534] [Citation(s) in RCA: 503] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although the crystal structures of the copper oxide high-temperature superconductors are complex and diverse, they all contain some crystal planes consisting of only copper and oxygen atoms in a square lattice: superconductivity is believed to originate from strongly interacting electrons in these CuO2 planes. Substituting a single impurity atom for a copper atom strongly perturbs the surrounding electronic environment and can therefore be used to probe high-temperature superconductivity at the atomic scale. This has provided the motivation for several experimental and theoretical studies. Scanning tunnelling microscopy (STM) is an ideal technique for the study of such effects at the atomic scale, as it has been used very successfully to probe individual impurity atoms in several other systems. Here we use STM to investigate the effects of individual zinc impurity atoms in the high-temperature superconductor Bi2Sr2CaCu2O8+delta. We find intense quasiparticle scattering resonances at the Zn sites, coincident with strong suppression of superconductivity within approximately 15 A of the scattering sites. Imaging of the spatial dependence of the quasiparticle density of states in the vicinity of the impurity atoms reveals the long-sought four-fold symmetric quasiparticle 'cloud' aligned with the nodes of the d-wave superconducting gap which is believed to characterize superconductivity in these materials.
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Deutscher G. Coherence and single-particle excitations in the high-temperature superconductors. Nature 1999; 397:410-412. [DOI: 10.1038/17075] [Citation(s) in RCA: 291] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/1998] [Accepted: 11/23/1998] [Indexed: 11/09/2022]
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Panagopoulos C, Cooper JR, Athanassopoulou N, Chrosch J. Effects of Zn doping on the anisotropic penetration depth of YBa2Cu3O7. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R12721-R12724. [PMID: 9985228 DOI: 10.1103/physrevb.54.r12721] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ziegler K, Hettler MH, Hirschfeld PJ. Nonzero Fermi Level Density of States for a Disordered d-Wave Superconductor in Two Dimensions. PHYSICAL REVIEW LETTERS 1996; 77:3013-3016. [PMID: 10062109 DOI: 10.1103/physrevlett.77.3013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Sato Y, Terasaki I, Tajima S. Seebeck and Nernst effects in the mixed state of YBa2Cu3Oy single crystals: A probe for the scattering rate of quasiparticles. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:6676-6679. [PMID: 9986686 DOI: 10.1103/physrevb.54.6676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Cooper JR. Power-law dependence of the ab-plane penetration depth in Nd1.85Ce0.15CuO4-y. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R3753-R3755. [PMID: 9986364 DOI: 10.1103/physrevb.54.r3753] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lee SF, Morgan DC, Ormeno RJ, Broun DM, Doyle RA, Waldram JR, Kadowaki K. a-b Plane Microwave Surface Impedance of a High-Quality Bi2Sr2CaCu2O8 Single Crystal. PHYSICAL REVIEW LETTERS 1996; 77:735-738. [PMID: 10062889 DOI: 10.1103/physrevlett.77.735] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Frenkel A, Gao F, Liu Y, Whitaker JF, Uher C, Hou SY, Phillips JM. Conductivity peak, relaxation dynamics, and superconducting gap of YBa2Cu3O7 studied by terahertz and femtosecond optical spectroscopies. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:1355-1365. [PMID: 9985408 DOI: 10.1103/physrevb.54.1355] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Jiang C, Schachinger E, Carbotte JP, Basov D, Timusk T. Imaginary part of the infrared conductivity of a dx2-y2 superconductor. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:1264-1272. [PMID: 9985398 DOI: 10.1103/physrevb.54.1264] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Bonn DA, Kamal S, Bonakdarpour A, Liang R, Hardy WN, Homes CC, Basov DN, Timusk T. Surface impedance studies of YBCO. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf02548130] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kim JT, Giapintzakis J, Ginsberg DM. Sign reversal of the Hall effect in superconducting YBa2(Cu1-xNix)3O7- delta single crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:5922-5926. [PMID: 9984202 DOI: 10.1103/physrevb.53.5922] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Cohn JL. Superconducting-state enhancement of thermal conductivity in the cuprates: Correlation with the pair density. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:R2963-R2966. [PMID: 9983896 DOI: 10.1103/physrevb.53.r2963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Käll M, Litvinchuk AP, Börjesson L, Berastegui P, Johansson L. Effects of Zn substitution for Cu on Raman phonon anomalies in double-chain YBa2Cu4O8 superconductors. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:3566-3572. [PMID: 9983872 DOI: 10.1103/physrevb.53.3566] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Fukuzumi Y, Mizuhashi K, Takenaka K, Uchida S. Universal superconductor-insulator transition and Tc depression in Zn-substituted high-Tc cuprates in the underdoped regime. PHYSICAL REVIEW LETTERS 1996; 76:684-687. [PMID: 10061521 DOI: 10.1103/physrevlett.76.684] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Krishana K, Harris JM, Ong NP. Quasiparticle mean free path in YBa2Cu3O7 measured by the thermal Hall conductivity. PHYSICAL REVIEW LETTERS 1995; 75:3529-3532. [PMID: 10059609 DOI: 10.1103/physrevlett.75.3529] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Borkowski LS, Hirschfeld PJ, Putikka WO. Transport properties of extended-s-state superconductors. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:R3856-R3859. [PMID: 9981611 DOI: 10.1103/physrevb.52.r3856] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Zimmermann P, Keller H, Lee SL, Savic IM, Warden M, Zech D, Cubitt R, Forgan EM, Kaldis E, Karpinski J, Krüger C. Muon-spin-rotation studies of the temperature dependence of the magnetic penetration depth in the YBa2Cu3Ox family and related compounds. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:541-552. [PMID: 9979633 DOI: 10.1103/physrevb.52.541] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Xu D, Yip SK, Sauls JA. Nonlinear Meissner effect in unconventional superconductors. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:16233-16253. [PMID: 9978609 DOI: 10.1103/physrevb.51.16233] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Shibata H, Semba K, Matsuda A, Yamada T. Infrared reflectivity of untwinned YBa2(Cu1-xZnx)3O7- delta single crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:9294-9297. [PMID: 9977571 DOI: 10.1103/physrevb.51.9294] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ulm ER, Kim JT, Lemberger TR, Foltyn SR, Wu X. Magnetic penetration depth in Ni- and Zn-doped YBa2(Cu1-xMx)3O7 films. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:9193-9198. [PMID: 9977561 DOI: 10.1103/physrevb.51.9193] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Klemm RA, Liu SH. Role of normal layers in penetration depth determinations of the pairing state in high-Tc superconductors. PHYSICAL REVIEW LETTERS 1995; 74:2343-2346. [PMID: 10057904 DOI: 10.1103/physrevlett.74.2343] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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41
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Zhang K, Bonn DA, Kamal S, Liang R, Baar DJ, Hardy WN, Basov D, Timusk T. Measurement of the ab plane anisotropy of microwave surface impedance of untwinned YBa2Cu3O6.95 single crystals. PHYSICAL REVIEW LETTERS 1994; 73:2484-2487. [PMID: 10057071 DOI: 10.1103/physrevlett.73.2484] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Kamal S, Bonn DA, Goldenfeld N, Hirschfeld PJ, Liang R, Hardy WN. Penetration depth measurements of 3D XY critical behavior in YBa2Cu3O6.95 crystals. PHYSICAL REVIEW LETTERS 1994; 73:1845-1848. [PMID: 10056901 DOI: 10.1103/physrevlett.73.1845] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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