TY - JOUR
T1 - Detection and control of broken symmetries with Andreev bound state tunneling spectroscopy
T2 - Proceedings of the International Conference on Materials
AU - Greene, L. H.
AU - Hentges, P. J.
AU - Aubin, H.
AU - Aprili, M.
AU - Badica, E.
AU - Covington, M.
AU - Pafford, M. M.
AU - Westwood, G.
AU - Klemperer, W. G.
AU - Jian, Sha
AU - Hinks, D. G.
N1 - Funding Information:
We acknowledge valuable discussions with A.V. Balatsky, D.M. Ginsberg, P.M. Goldbart, M. Fogelström, A.J. Leggett, T. Löfwander, M. Randeria, J.A. Sauls, D. Sheehey and N. Trevidi, and technical assistance from W.L. Feldmann. This work is supported by the U.S. DoE-DMR: DEFG02-ER9645439, through the FS-MRL, with additional support for LHG and PJH from NSF-DMR 99-72087. Materials characterization was carried out in the UIUC-CMM, partially supported by the U.S. DoE: DEFG02-91-ER45439.
PY - 2004/8
Y1 - 2004/8
N2 - 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.
AB - 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.
KW - Andreev bound states
KW - Broken time-reversal symmetry
KW - High-temperature superconductivity
KW - Planar tunneling spectroscopy
KW - Unconventional superconducivity
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U2 - 10.1016/j.physc.2004.03.138
DO - 10.1016/j.physc.2004.03.138
M3 - Conference article
AN - SCOPUS:4444261059
VL - 408-410
SP - 804
EP - 806
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-4
Y2 - 25 May 2003 through 30 May 2003
ER -