Transport properties of strongly correlated metals: A dynamical mean-fieldapproach

The temperature dependence of the transport properties of the metallic phas e of a frustrated Hubbard model on the hypercubic lattice at half-filling i s calculated. Dynamical mean-held theory, which maps the Hubbard model onto a single impurity,Anderson model that is solved self-consistently, and bec omes exact in the limit of large dimensionality, is used. As the temperatur e increases there is a smooth crossover from coherent Fermi liquid excitati ons at low temperatures to incoherent excitations at high temperatures. Thi s crossover leads to a nonmonotonic temperature dependence for the resistan ce, thermopower, and Hall coefficient, unlike in conventional metals. The r esistance smoothly increases from a quadratic temperature dependence at low temperatures to large values which can exceed the Mott-Ioffe-Regel value h a/e(2) (where a is a lattice constant) associated with mean free paths less than a lattice constant. Further signatures of the thermal destruction of quasiparticle excitations are a peak in the thermopower and the absence of a Drude peak in the optical conductivity. The results presented here are re levant to a wide range of strongly correlated metals, including transition metal oxides, strontium ruthenates, and organic metals.