Electronic relaxation rates in metallic ferromagnets

Article

关键词: ELECTRICAL-RESISTIVITY;    WEAK FERROMAGNETISM;    QUANTUM;    PHASE;    TRANSITION;    BEHAVIOR;    FERMI;   

DOI  :  10.1103/PhysRevB.89.134401

来源: SCIE

【 摘 要 】

We show that the magnon-exchange contribution to the single-particle and transport relaxation rates in ferromagnetic metals, which determine the thermal and electrical conductivities, respectively, at asymptotically low temperatures does not obey a power law as previously thought, but rather shows an exponential temperature dependence. The reason is the splitting of the conduction band, which inevitably results from a nonzero magnetization. At higher temperatures, there is a sizable temperature window where the transport rate shows a T 2 temperature dependence, in accord with prior results. This window is separated from the asymptotic regime by a temperature scale that is estimated to range from tens of millidegrees of Kelvin to tens of degrees of Kelvin for typical ferromagnets. We motivate and derive a very general effective theory for metallic magnets that we then use to derive these results. Comparisons with existing experiments are discussed, and predictions for future experiments at low temperatures are made.

【 授权许可】

Free