Detection and control of broken symmetries with Andreev bound state tunneling spectroscopy: Effects of atomic-scale disorder

L. H. Greene, P. J. Hentges, H. Aubin, M. Aprili, E. Badica, M. Covington, M. M. Pafford, G. Westwood, W. G. Klemperer, Sha Jian, D. G. Hinks

Research output: Contribution to journalConference articlepeer-review

Abstract

Quasiparticle planar tunneling spectroscopy is used to study unconventional superconductivity in YBa2Cu3O7 (YBCO) thin films and Bi2Sr2CaCu2O8 (BSCCO) single crystals. Tunneling conductances are obtained as a function of crystallographic orientation, applied magnetic field (magnitude and orientation), atomic substitution and surface damage. Our systematic studies confirm that the observed zero-bias conductance peak (ZBCP), a measure of the near-surface quasiparticle (QP) density of states (DoS), is comprised of Andreev bound states (ABS) resulting directly from the sign change of the d-wave order parameter (OP) at the Fermi surface. Our data, plus a literature search, reveals a consistency in the observation of the splitting of the ZBCP in optimally-doped materials. We note that the splitting of the ZBCP observed in applied field, and the spontaneous splitting observed at lower temperatures in zero field, occur concomitantly in a given junction, and that observation of this splitting is dependent upon two parameters: (1) the magnitude of the tunneling cone and (2) the degree of atomic-scale disorder at the interface.

Original languageEnglish (US)
Pages (from-to)804-806
Number of pages3
JournalPhysica C: Superconductivity and its applications
Volume408-410
Issue number1-4
DOIs
StatePublished - Aug 2004
EventProceedings of the International Conference on Materials - Rio de Janeiro, Brazil
Duration: May 25 2003May 30 2003

Keywords

  • Andreev bound states
  • Broken time-reversal symmetry
  • High-temperature superconductivity
  • Planar tunneling spectroscopy
  • Unconventional superconducivity

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Detection and control of broken symmetries with Andreev bound state tunneling spectroscopy: Effects of atomic-scale disorder'. Together they form a unique fingerprint.

Cite this