Interplay of disorder and spin fluctuations in the resistivity near a quantum critical point

The resistivity in metals near an antiferromagnetic quantum critical point (QCP) is strongly affected by small amounts of disorder. In a quasiclassical treatment, we show that an interplay of strongly anisotropic scattering due to spin fluctuations and isotropic impurity scattering leads to a large regime where the resistivity varies as T-alpha, with an anomalous exponent, 1 less than or equal to alpha less than or equal to 1.5, depending on the amount of disorder. I argue that this mechanism explains in some detail the anomalous temperature dependence of the resistivity observed in CePd2Si2, CeNi2Ge2, and CeIn3 near the QCP. [S0031-9007(99)09253-4].