Microscopic Theory of Magnon-Drag Thermoelectric Transport in Ferromagnetic Metals

概要

論文の詳細を見る
A theoretical study of the magnon-drag Peltier and Seebeck effects in ferromagnetic metals is presented. A magnon heat current is described perturbatively from the microscopic viewpoint with respect to electron--magnon interactions and the electric field. Then, the magnon-drag Peltier coefficient \Pi_{\text{mag}} is obtained as the ratio between the magnon heat current and the electric charge current. We show that \Pi_{\text{mag}}=C_{\text{mag}} T^{5/2} at a low temperature T; that the coefficient C_{\text{mag}} is proportional to the spin polarization P of the electric conductivity; and that P>0 for C_{\text{mag}}<0, but P<0 for C_{\text{mag}}>0. From experimental results for magnon-drag Peltier effects, we estimate that the strength of the electron--magnon interaction is about 0.3 eV\cdotÅ3/2 for permalloy.
2012-11-15