Nodeless Pairing State in Single-Crystal YBa2Cu3O7
01 January 2004
Our results (i) confirm the s-wave superconductivity character originally observed in 1989, and (ii) show that the features of muSR (and microwave) data claimed by other authors to be evidence for d-wave superconductivity are instead symptomatic of temperature-dependent de-pinning of vortices, which results in long-ranged distortion of the flux lattice. Indeed, the probability that any d-wave model gives a better fit than the two-fluid s-wave model is less than 4 x 10 sup -6.