Thermoelectric power of heavy fermions by renormalization group calculations

Abstract

Abstract The thermopower of heavy fermions based on the CeCu, CeB and YbCu intermetallics doped with non-magnetic impurities like Al, Ag, Au and Ga is discussed using the single impurity Anderson model with more than one scattering channel with correlation effects in the resonant channel taken into account by the numerical renormalization group method. The typical shape of the experimental curves is related to the change in the structure of the low-energy excitations induced by the variation of the temperature on the characteristic scale (the Kondo scale, T K , or the scale of valence fluctuators, Δ). The observed sensitivity of the sign of the thermopower to small changes of the local environment around the magnetic ions is attributed to the interference between the resonant and the non-resonant scattering.