Superconducting gap structure of spin-triplet superconductor Sr2RuO4 studied by thermal conductivity

To clarify the superconducting gap structure of the spin-triplet supercondu ctor Sr2RuO4, the in-plane thermal conductivity has been measured as a func tion of relative orientations of the thermal flow, the crystal axes, and a magnetic field rotating within the 2D RUO2 planes. The in-plane variation o f the thermal conductivity is incompatible with any model with line nodes v ertical to the 2D planes and indicates the existence of horizontal nodes. T hese results place strong constraints on models that attempt to explain the mechanism of the triplet superconductivity.