Enhancement of thermal transport in the degenerate periodic Anderson model

The low-temperature transport coefficients of the degenerate periodic SU(N) Anderson model are calculated in the limit of infinite correlation between {\it f} electrons, within the framework of dynamical mean-field theory. We establish the Fermi liquid (FL) laws in the clean limit, taking into account the quasiparticle damping. The latter yields a reduced value of the Lorenz number in the Wiedemann-Franz law. Our results indicate that the renormalization of the thermal conductivity and of the Seebeck coefficient can lead to a substantial enhancement of the electronic thermoelectric figure-of-merit at low temperature. Using the FL laws we discuss the low-temperature anomalies that show up in the electrical resistance of the intermetallic compounds with Cerium and Ytterbium ions, when studied as a function of pressure. Our calculations explain the sharp maximum of the coefficient of the $T^2$-term of the electrical resistance and the rapid variation of residual resistance found in a number of Ce and Yb intermetallics at some critical pressure.