Impurity Effects in Nodal Extendeds- and Nodelessd-Wave Superconductors: Gap Symmetry of BiS2-Based Layered Superconductors

Gap Symmetry and Thermal Conductivity in Nodal Superconductors

There are now many nodal superconductors in heavy fermion (HF) systems, charge conjugated organic metals, high Tc cuprates and ruthenates. On the other hand only few of them have well established ∆(k). We present here a study of the angular dependent thermal conductivity in the vortex state of some of the nodal superconductors. We hope it will help to identify the nodal directions in ∆(k) of UP...

Gap Symmetry and Thermal Conductivity in Nodal Superconductors

Here we consider the universal heat conduction and the angular dependent thermal conductivity in the vortex state for a few nodal superconductors. We present the thermal conductivity as a function of impurity concentration and the angular dependent thermal conductivity in a few nodal superconductors. This provides further insight in the gap symmetry of superconductivity in Sr2RuO4 and UPd2Al3.

Anomalous impurity effects in nonadiabatic superconductors

– We show that, in contrast with the usual electron-phonon Migdal-Eliashberg theory, the critical temperature Tc of an isotropic s-wave nonadiabatic superconductor is strongly reduced by the presence of diluted non-magnetic impurities. Our results suggest that the recently observed Tc-suppression driven by disorder in K3C60 (Phys. Rev. B 55, 3866 (1997)) and in Nd2−xCexCuO4−δ (Phys. Rev. B 58, ...

Impurity Eeects in Superconductors

d-wave pairing symmetry in cuprate superconductors

Phase-sensitive tests of pairing symmetry have provided strong evidence for predominantly d-wave pairing symmetry in both the holeand electron-doped high-Tc cuprate superconductors. Temperature dependent measurements in YBa2Cu3O7−δ (YBCO) indicate that the d-wave pairing dominates, with little if any imaginary component, at all temperatures from 0.5K through Tc. In this article we review some o...