Tunneling Spectroscopy on c-axis Y{1-x}Ca{x}Ba2Cu3O{7-delta} Thin Films

TL;DR

This study uses tunneling spectroscopy on Ca-doped YBCO thin films to analyze their superconducting gap features, revealing multi-band superconductivity involving chain and plane bands.

Contribution

It introduces a multiband tunneling model to explain spectral features, highlighting the role of chain and plane bands in superconductivity.

Findings

Main-gap, sub-gap, and satellite features scale with Ca-doping.

Sub-gap features linked to chain band, main-gap and satellite to plane band.

Results support multi-band superconductivity in YCaBaCuO.

Abstract

Scanning tunneling spectroscopy was performed on c-axis Y{1-x}Ca{x}Ba2Cu3O{7-delta} thin films for x= 0, 0.05, 0.15 and 0.20 at 4.2K. The measured spectra show main-gap, sub-gap and satellite features which scale similarly in energy versus Ca-doping, suggesting that they are associated with a single pairing energy. The data is analyzed with a multiband tunneling model which attributes the sub-gap features to the chain band and the satellite and main-gap features to the plane band for d+s pairing symmetry. These results suggest that the superconductivity in Y{1-x}Ca{x}Ba2Cu3O{7-delta} involves multiple bands.