Two-Band Superconductivity in Nb-Doped SrTiO3

著者: G. Binnig, A. Baratoff, H. E. Hoenig, J. G. Bednorz - Physical Review Letters 1980 被引用: 281

Tunneling measurements have been performed on Nb-doped and reduced superconducting SrTi${\mathrm{O}}_{3}$. Beyond a certain carrier concentration, when a second conduction band gets filled, a distinctive double-gap structure is observed in Nb-doped samples. Its sharpness and anomalous temperature dependence can be related to the onset of two-band superconductivity in accordance with theoretical expectations. The observation of a single gap $\ensuremath{\Delta}\ensuremath{\simeq}1.76 k{T}_{c}$ in reduced SrTi${\mathrm{O}}_{3}$ is attributed to enhanced interband scattering.