The effect of phonon drag on the electrical resistivity of metals at low temperatures

Abstract

From a perturbative solution of the transport equations for an electron-phonon system in the region where impurity scattering dominates, Dworin (1971) has obtained an expression for the phonon drag contribution to the electrical resistivity. The author shows that this formal result may be simply obtained by the variational method. But Dworin's evaluation of the expression, which gives an additional resistivity varying as T3 and a corresponding T4 term in the thermopower is questionable since general physical considerations imply that the effect of phonon drag is to reduce the resistivity. Experimental evidence for the effect of phonon drag on low temperature resistivity is briefly considered and the interpretation of recent results on the resistivity and thermopower of high purity copper (Rumbo 1973) is discussed.