Experimental Observation of Non-'S-Wave' Superconducting Behavior in Bulk Superconducting Tunneling Junctions of Yba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>

  • Leandro Jose Guerra
  • Flordivino Basco
  • Roland Sarmago

Abstract

Evidence of non-s-wave superconductivity from normal tunneling experiments in bulk tunneling junctions of YBa2Cu3O7-δ is presented. The I-V and dI/dV characteristics of bulk superconducting tunneling junctions of YBa2Cu3O7-δ have been measured at 77.0K and clear deviation from s-wave superconducting behavior has been observed. The result agrees with d-wave symmetry, and interpreting the data in this way, the magnitude of the superconducting energy gap, 2Δ, is found to be (0.038 ± 0.002) eV. Comparing this energy gap with Tc (2Δ/kB Tc = 5.735), indicates that these high-Tc superconductors are strongly correlated materials, which in contrast with BCS-superconductors are believed to be weakly correlated.
Published
2007-09-19
Section
Articles