Pair Symmetry and Degree of Gap Depression at S-I Interfaces in HTS Josephson Junctions

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1301-1306
Author(s):  
G. A. Ummarino ◽  
R. S. Gonnelli ◽  
C. Bravi ◽  
Masumi Inoue
Keyword(s):  
Josephson Junctions ◽  
Order Parameter ◽  
Reference Value ◽  
High Tc Superconductors ◽  
S Wave ◽  
General Reference ◽  
High Tc ◽  
Wave Symmetry ◽  
Set Up ◽  
D Wave

A new possible indirect way of testing pair symmetry in high-Tc superconductors has been set up. The degree of intrinsic gap depression at Superconductor-Insulator [S-I] interfaces required to match Ic(T)Rn(T) data in HTS Josephson junctions depends on the pair symmetry of the material itself, so that an higher fraction of d-wave symmetry for the order parameter requires less gap depression, while an higher fraction of s-wave corresponds to a larger degree of gap depression. In order to obtain a general reference value for the intrinsic amount of gap depression at S-I interfaces the de Gennes condition has been used, and resulting reduced Ic(T)Rn(T) data have been calculated in the framework of a mixed (s+id)-wave pair symmetry for the depressed order parameter ranging from pure s to pure d-wave. This model has been tentatively applied to two junctions' made of very different HTSs: YBCO and BKBO, yielding a result of almost pure d-wave for YBCO and of pure s-wave for BKBO.

On the Origin of Zero-Bias Conductance Peak in High-Tc Superconductors

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3027-3030
Author(s):  
Alexander B. Nazarenko ◽  
Ernst A. Pashitskii ◽  
Alexander E. Pashitskii
Keyword(s):  
Elastic Scattering ◽  
Order Parameter ◽  
Magnetic Impurities ◽  
High Tc Superconductors ◽  
Zero Bias ◽  
High Tc ◽  
Conductance Peak ◽  
Wave Symmetry ◽  
Zero Bias Conductance ◽  
D Wave

We show that the zero-bias conductance peak observed in tunnel and point junctions of cuprates can be a consequence of "unitary" elastic scattering of the carriers by non-magnetic impurities in the vicinity of the junction interface and d-wave symmetry of the order parameter.

Effects of d-wave symmetry in high Tc step-edge Josephson junctions

2000 ◽  
Vol 341-348 ◽  
pp. 1473-1474 ◽  
Author(s):  
Soon-Gul Lee ◽  
Yunseok Hwang ◽  
Jin-Tae Kim ◽  
Gun Yong Sung
Keyword(s):  
Josephson Junctions ◽  
Step Edge ◽  
High Tc ◽  
Wave Symmetry ◽  
D Wave

scholarly journals Suppression of the s-Wave Order Parameter Near the Surface of the Infinite-Layer Electron-Doped Cuprate Superconductor Sr0.9La0.1CuO2

2020 ◽  
Vol 5 (3) ◽  
pp. 50
Author(s):  
Rustem Khasanov ◽  
Alexander Shengelaya ◽  
Roland Brütsch ◽  
Hugo Keller
Keyword(s):  
Order Parameter ◽  
Muon Spin ◽  
Muon Spin Rotation ◽  
Wave Component ◽  
S Wave ◽  
Infinite Layer ◽  
Wave Symmetry ◽  
Out Of Plane ◽  
The Magnetic Field ◽  
D Wave

The temperature dependencies of the in-plane (λab) and out-of-plane (λc) components of the magnetic field penetration depth were investigated near the surface and in the bulk of the electron-doped superconductor Sr0.9La0.1CuO2 by means of magnetization measurements. The measured λab(T) and λc(T) were analyzed in terms of a two-gap model with mixed s+d-wave symmetry of the order parameter. λab(T) is well described by an almost pure anisotropic d-wave symmetry component (≃96%), mainly reflecting the surface properties of the sample. In contrast, λc(T) exhibits a mixed s+d-wave order parameter with a substantial s-wave component of more than 50%. The comparison of λab−2(T) measured near the surface with that determined in the bulk by means of the muon-spin rotation/relaxation technique demonstrates that the suppression of the s-wave component of the order parameter near the surface is associated with a reduction of the superfluid density by more than a factor of two.

Evidence for d-wave symmetry in high-Tc superconductors based on tunneling theory and STM experiment

1994 ◽  
Vol 235-240 ◽  
pp. 1911-1912
Author(s):  
S. Kashiwaya ◽  
Y. Tanaka ◽  
M. Koyanagi ◽  
H. Takashima ◽  
K. Kajimura
Keyword(s):  
High Tc Superconductors ◽  
High Tc ◽  
Wave Symmetry ◽  
D Wave ◽  
Tunneling Theory

scholarly journals Aspects of Optical Properties in Conventional and Oxide Superconductors

1997 ◽  
Vol 50 (6) ◽  
pp. 975 ◽  
Author(s):  
F. Marsiglio ◽  
J. P. Carbotte
Keyword(s):  
Inelastic Scattering ◽  
Oxide Superconductors ◽  
S Wave ◽  
Temperature Dependent ◽  
High Tc ◽  
The Real ◽  
Scattering Rate ◽  
Wave Symmetry ◽  
High Tc Cuprates ◽  
D Wave

We review the effect of elastic and inelastic scattering on the normal state infrared conductivity, and describe modifications to the real and imaginary parts which result from a transition to an s-wave superconducting state. The zero frequency limit of the imaginary part is related to the temperature-dependent penetration depth and, at finite frequency, provides information about the superconducting gap. In the high Tc cuprates the gap appears to have d-wave symmetry. This profoundly modifies both the real and the imaginary parts of the optical conductivity. After describing these modifications we introduce the conductivity-derived scattering rate, which directly probes the inelastic scattering processes, and is much larger in the oxides than in conventional superconductors. This quantity is also significantly modified by the d-wave symmetry of the gap.

Ac Susceptibility Studies of the High Tc Superconductors: Dissipative Effects in La2.xSrxCuO4-Y and YBa2Cu3O7-Y Systems

1989 ◽  
Vol 169 ◽  
Author(s):  
Xinsheng Ling ◽  
M. E. Filipkowski ◽  
E. K. Heller ◽  
J. I. Budnick
Keyword(s):  
Grain Boundaries ◽  
Order Parameter ◽  
Ac Susceptibility ◽  
Similar Process ◽  
Charge Carrier Density ◽  
High Tc Superconductors ◽  
High Tc ◽  
Spatial Fluctuation ◽  
Dissipative Effects ◽  
Ceramic Samples

AbstractWe have studied the variation of dissipative effects with doping in the high Tc superconductors La2-xSrxCuO4-y and YBa2Cu3O7-y by studying the lossy component of ac susceptibility as a function of temperature. We find relatively strong excess losses at low temperature in both systems, which indicate stronger flux creep at grain boundaries, in lower level doped ceramic samples produced by a similar process. This effect is more significant in the La2-xSrxCuO4-y (214) system than in the YBa2Cu3O7-y(123) system. We suggest that the microscopic mechanisms of weakening of the order parameter in the grain boundaries may be different in the two systems. In the 214 system, as the charge carrier density in the CuO2 planes is reduced, the spatial fluctuation of the order parameter in the CuO2 planes is enhanced. In the 123 system, the initial removal of O from the sample, which weakens the coupling between planes and increases the spatial fluctuation of the order parameter between CuO2 planes. The grain boundaries are degraded in both systems. The degradation in the 214 samples is more significant than in the 123 samples.

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