Scanning tunneling spectroscopy of a-axis YBa_2Cu_3O_7-δfilms:k-selectivity and the shape of the superconductor

Abstract

Tunneling spectroscopy of epitaxial (100) oriented \chem{YBa_2Cu_3O_{7-δ}} films was performed using an STM at 4.2 K. On atomically smooth areas, tunneling spectra revealing clear U-shaped gaps with relatively low zero bias conductance were measured. These spectra can be well fitted to the tunneling theory into a d-wave superconductor only when introducing a strong dependence of the tunneling probability on the wave-vector \emph{\textbf{k}}. Possible origins for this \emph{\textbf{k}}-selectivity in STM measurements will be discussed. On other areas, V-shaped gaps as well as zero bias conductance peaks are observed, indicating relaxation of \emph{\textbf{k}}-selectivity and the effect of nanofaceting, respectively.

arXiv comment7 epl pages, 4 embeded figures

References in corpus (7)

• Tunneling into Current-Carrying Surface States of High T${}_c$ Superconductors
• Quasiparticle Bound States and Low-Temperature Peaks of the Conductance of NIS Junctions in d-Wave Superconductors
• Impurity states and interlayer tunneling in high temperature superconductors
• Local and macroscopic tunneling spectroscopy of Y(1-x)CaxBa2Cu3O(7-d) films: evidence for a doping dependent is or idxy component in the order parameter
• Atomic Scale Imaging and Spectroscopy of a CuO_2 Plane at the Surface of Bi_2Sr_2CaCu_2O_{8+delta}
• Correlation of tunneling spectra with surface nano-morphology and doping in thin YBa2Cu3O7-delta films
• Spatial homogeneity and doping dependence of quasiparticle tunneling spectra in cuprate superconductors

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