2001/11/09 by A. Sharoni O. Millo, Amos Sharoni, A. Kohen +6 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.65.134526
published as Physical Review B, 65, 134526 (March 2002)
arxiv created 2001/11/09 · openalex publication_date 2002/03/29 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Tunneling spectroscopy of epitaxial (110) Y_1\ensuremath-xCaxBa2Cu3O_7\ensuremath-\ensuremathδ films reveals a doping-dependent transition from a pure d_x2\ensuremath-y2 to d_x2\ensuremath-y2+is or d_x2\ensuremath-y2+idxy order parameter. The subdominant (is or idxy) component manifests itself in a splitting of the zero-bias conductance peak and the appearance of subgap structures. The splitting is seen in the overdoped samples, increases systematically with doping, and is found to be an inherent property of the overdoped films. It was observed in both local tunnel junctions, using scanning tunneling microscopy (STM), and in macroscopic planar junctions, for films prepared by either sputtering or laser ablation. The STM measurements exhibit a fairly uniform splitting size in [110] oriented areas on the order of 10nm2 but vary from area to area, indicating some doping inhomogeneity. U- and V-shaped gaps were also observed, with good correspondence to the local faceting, a manifestation of the dominant d-wave order parameter.