Disorder effects on transport near AFM quantum phase transitions

We discuss three different scenarios recently proposed to account for the n on-Fermi liquid behavior near antiferromagnetic (AFM) quantum critical poin ts in heavy-Fermion systems: (i) scattering of Fermi liquid quasiparticles by strong spin fluctuations near the spin-density-wave instability, (ii) th e breakdown of the Kondo effect due to the competition with the RKKY intera ction, and (iii) the formation of magnetic regions due to rare configuratio ns of the disorder. Here we focus on the first scenario and show that it ex plains in some detail the anomalous temperature dependence of the resistivi ty observed, e.g. in CePd2Si2, CeNi2Ge2 or CeIn3. The interplay of strongly anisotropic scattering due to critical spin-fluctuations and weak isotropi c impurity scattering leads to a regime with a resistivity rho approximate to rho(0) + Delta rho(T), Delta rho(T) = T(3/2)f(T/rho(0)) proportional to T root rho(0) for sufficiently large T and small rho(0). (C) 2000 Elsevier Science B.V. All rights reserved.