Tunneling spectra were observed in normal-metalinsulatorsuperconductor junctions fabricated from single-crystal films of YBa2Cu3O7-x(001), epitaxially grown on SrTiO3(100). The quasiparticle density of states observed in the perpendicular direction to the Cu-O planes exhibits a lifetime broadening picture of quasiparticles at the gap edges. The broadening parameter increases with an increase of the temperature. The recombination lifetime at 60 K is estimated to be 10-13 s. A gap parameter "S (4.6 K) of 9.0±1.8 meV and a coupling constant of (2.4±0.5)<2"S (0)/kTc <(3.5±0.7) were obtained.
ASJC Scopus subject areas
- Condensed Matter Physics