Low temperature magnetic penetration depth in d-wave superconductors

We briefly review the experimental results of the low temperature magnetic penetration depth (T) of d-wave superconductors. In very clean high-T-c superconductors (HTSC) the low temperature in-plane penetration depth lambda(vertical bar vertical bar)(T) varies linearly with T. A weaker power law temperature dependence is found for the out-of-plane penetration depth (7) in most of HTSC. In the organic superconductors kappa-(BEDT-TTF)(2)X, [X=Cu(NCS)(2), Cu[N(CN)(2)]Br] and slightly dirty HTSC lambda vertical bar vertical bar proportional to bT(2)/(T*+T), where T* approximate to root Gamma Delta(0) is deduced from an impurity scattering model. In clean CeCoIn5 a crossover from linear to quadratic temperature behavior at low T was interpreted as the first evidence for nonlocal effects in a al-wave superconductor. (c) 2005 Elsevier Ltd. All rights reserved.