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

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.

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.

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 Qualitative Picture of a New Mechanism for High-Tc Superconductors

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3284-3292
Author(s):  
Chia-Ren Hu
Keyword(s):  
Short Range ◽  
Coulomb Repulsion ◽  
Tunneling Conductance ◽  
High Tc Superconductors ◽  
Nernst Effect ◽  
High Tc ◽  
Ferromagnetic Order ◽  
Wave Nature ◽  
Qualitative Picture ◽  
D Wave

Xu et al. observed enhanced Nernst effect and Iguchi et al. observed patched diamagnetism, both well above Tc in underdoped high-Tc superconductors (HTSCs). A new mechanism is proposed here, which seems to naturally explain, at least qualitatively, these observations, as well as the d-wave nature and continuity of pseudogap and pairing gap, the tunneling conductance above Tc, as well as T*(x), Tν(x), Tc(x), etc. This mechanism combines features of dynamic charged stripes, preformed pairs, and spin-bags: At appropriete doping levels, the doped holes (and perhaps also electrons) will promote the formation of anti-phase islands in short-range anti-ferromagnetic order. On the boundary of each such island reside two doped carriers; the unscreened Coulomb repulsion between them stabilizes the island's size. Superconductivity results when such "pre-formed pairs" Bose-condense.

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