On the electrical resistivity of spin glasses

The resistivity of spin glasses with momentum independent static susceptibility_k= due to the disorder of the spin system and to spin excitations is calculated to lowest order in the temperatureT, and above the freezing temperatureT_f. The diffusive modes proposed by Dzyaloshinskii and Volovik lead for to a resistivity of the form=AT² –BT^5/2 with positive coefficientsA andB. TheT^3/2 contribution observed by Ford and Mydosh can be explained by the existence of ferromagnetic clusters. For, a classical theory with 1 for all excitation energies and with_k= leads to a constant resistivity (the Yosida limit). The observed increase of the resistivity aboveT_f can be explained by rather strong magnetic short range order.SFB 125 Aachen-Jülich-Köln