Striking similarities between HTSC and quasi-2D HF CeRIn₅

We report our measurements of transport coefficients of quasi-2D HF CeRIn₅ in the normal state, in the vicinity of a QCP and in the superconducting state. In the normal state, we observed a T-linear resistivity, a T²-dependence of cot θ_H (θ_H is the Hall angle), the violation of Kohler's rule, and a giant Nernst coefficient. In the superconducting state, on the other hand, we found a rapid increase of the quasiparticle (QP) mean free path as the temperatures is reduced below T_c. The density of states (DOS) of delocalized QPs obtained from the thermal Hall coefficient is consistent with a d-wave pairing symmetry. Moreover, the angular dependence of thermal conductivity indicates that the gap function has a d-wave symmetry with line nodes perpendicular to the ab-plane. These results bear a striking resemblance to those obtained for the high-T_c cuprates. This similarity implies that the fluctuation and excitation spectrum near a 2D antiferromagnetic QCP could be universal.