High-temperature superconductivity: The hole-pairing is s-wave, and the holes are on the SrO, BaO, or interstitial oxygen

• Published in: Journal of low temperature physics 2003-05, Vol.131 (3-4), p.483-492
• Main Authors: DOW, John D, HARSHMAN, Dale R
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure; Exact sciences and technology; Physics; Properties of type I and type II superconductors; Response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.); Superconductivity
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1023/A:1022947102317

Muon spectroscopy experiments (*m+SR) on YBa2Cu3O7 have shown since 1987 that the hole-pairing is s-wave rather than d-wave (as claimed in 1994 by Sonier et al.). New data taken for a high-quality crystal in a large applied field of 60 kOe show that the claims of d-wave pairing are invalid and based on a misinterpretation of what is actually fluxon-reordering. Several experiments have shown that the holes of high-Tc superconducting oxides reside in the SrO, BaO, or interstitial oxygen regions, and not in the cuprate-planes. These include: (i) successful predictions that PrBa2Cu3O7 and three other compounds would superconduct, because the superconductivity is in the BaO or SrO layers (not in the cuprate-planes); (ii) successful demonstration that a Pr-on-a-Ba-site defect (above a cuprate-plane) is a magnetic pair-breaker that kills superconductivity, but that Pr-on-a-Pr site (below the plane) does not destroy superconductivity, although the two sites are virtually the same distance from the cuprate-plane; (iii) evidence that cuprate-plane-free Sr2YRuO6 has an onset of superconductivity at #~49 K when doped with Cu on Ru sites, which nearly coincides with the onset temperatures of R2-zCexSr2Cu2RuO10 (for R=Eu or Gd) and GdSr2Cu2RuO8, presumably because the SrO layers, not the CuO2 planes, superconduct in all three types of compounds; (iv) data indicating that all high-temperature oxide superconductors are p-type and have electronically paired holes; and (v) evidence that the pairing is similar for the cuprates and the ruthenates, and for some organics where sulfur carries the holes.