Anisotropic conductivity in superconducting NCCO

The low temperature behaviour of the in-plane and c-axis conductivity of electron-doped cuprates like NCCO is examined; it is shown to be consistent with an isotropic quasiparticle scattering rate and an anisotropic interlayer hopping parameter which is non-zero for planar momenta along the direction of the d$_{x^2-y^2}$ order parameter nodes. Based on these hypotheses we find that both, the in-plane and the c-axis conductivity, vary linearly with temperature, in agreement with experimental data at millimiter-wave frequencies.