Probing the nodal structure in quasi-2D unconventional superconductors by thermal conductivity Original Research Article

The superconducting gap structure is an unresolved issue in most of unconventional superconductors. Here we measured the thermal conductivity of 2D unconventional superconductors, spin-triplet Sr2RuO4, heavy fermion CeCoIn5 and organic κ-(BEDT-TTF)2Cu(NCS)2, in magnetic field rotating within the 2D planes. On the basis of the angular variation in the thermal conductivity, we demonstrate that the gap function is for Sr2RuO4, dx2−y2 for CeCoIn5, and dxy for κ-(BEDT-TTF)2Cu(NCS)2.