Effect of Magnon–Magnon Drag on Spin-Wave Current in Metal/Magnetic-Insulator Structures

Abstract

This paper presents the results of our investigation of the formation and interaction of two injected and thermally excited energetically distinguishable magnon fluxes and phonon flux in metal/magnetic-insulator structures and their influence on spin-wave current and drag effect. These have been studied under the conditions of the spin Seebeck effect. In the approximation of effective parameters, when the fluxes of magnons and phonons are characterized by their specific drift velocities and effective temperatures, we constructed macroscopic equations of the balance of the momenta of each of the subsystems in question. The analysis of the macroscopic equations was performed at different relationships between the drift velocities of these fluxes. The study has shown that it is possible that the basic channel of scattering of the injected magnons is the interaction with thermal magnons, and it is precisely this interaction that determines the temperature–field dependences of the spin-wave current under the conditions of spin Seebeck effect.