Microscopic Theory of Magnon-Drag Thermoelectric Transport in Ferromagnetic Metals

الأصل · EN

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 Π is obtained as the ratio between the magnon heat current and the electric charge current. We show that Π=C T⁵/² at a low temperature T; that the coefficient C is proportional to the spin polarization P of the electric conductivity; and that P>0 for C<0, but P<0 for C>0. From experimental results for magnon-drag Peltier effects, we estimate that the strength of the electron--magnon interaction is about 0.3 eV·Å³/² for permalloy.