With improved signal-averaging techniques, the tunneling conductance from pulsed-laser-deposited films of ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathrm{\delta }}$ reveals a rich fine structure in both the subgap and near-gap regions. A comparison of this structure with calculations by Tachiki et al. yields excellent agreement and indicates the origin of the fine structure is the density of electronic states on the different layered planes of this high-${\mathit{T}}_{\mathit{c}}$ material.

• Received 23 April 1993

DOI:https://doi.org/10.1103/PhysRevB.48.7499