title: Anomalous proximity effect in gold coated (110) YBa2Cu3O7-delta films: penetration of the Andreev bound states.
abstract: Scanning tunneling spectroscopy of (110)YBa(2)Cu(3)O(7-delta)/Au bilayers reveal a proximity effect markedly different from the conventional one. While proximity-induced mini-gaps rarely appear in the Au layer, the Andreev bound states clearly penetrate into the metal. Zero bias conductance peaks are measured on Au layers thinner than 7 nm with a magnitude similar to those detected on the bare superconductor films. The peaks then decay abruptly with Au thickness and disappear above 10 nm. This length is shorter than the normal coherence length and corresponds to the (ballistic) mean free path.
authors.affiliation: Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
authors.forename: Itay
authors.initials: I
authors.lastname: Asulin
authors.forename: Amos
authors.initials: A
authors.lastname: Sharoni
authors.forename: Ofer
authors.initials: O
authors.lastname: Yulli
authors.forename: Gad
authors.initials: G
authors.lastname: Koren
authors.forename: Oded
authors.initials: O
authors.lastname: Millo