We have obtained strong experimental evidence for the full determination of the superconducting gap structure in all three bands of the spin-triplet superconductor Sr2RuO4 for the first time. We have extended the measurements of the field-orientation dependent specific heat to include conical field rotations consisting of in-plane azimuthal angle φ-sweeps at various polar angles θ performed down to 0.1 K. Clear 4-fold oscillations of the specific heat and a rapid suppression of it by changing θ are explained only by a compensation from two types of bands with anti-phase gap anisotropies with each other. The results indicate that the active band, responsible for the superconducting instability, is the γ-band with the lines of gap minima along the  directions, and the passive band is the α- and β-bands with the lines of gap minima or zeros along the  directions in their induced superconducting gaps. We also demonstrated the scaling of the specific heat for the field in the c-direction, which supports the line-node-like gap structures running along the kz direction.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)