MAGNONS HEAT TRANSPORT AT AN INTEGRATED NANOSTRUCTURE IN ULTRATHIN HEISENBERG FERROMAGNETIC FILMS

摘要

A theoretical model is presented for the study of magnons heat transfer across an integrated nanostructure acting as interface material between two ultrathin Heisenberg ferromagnetic films. This is done by calculating the transmission rates of the spill wave modes through the consideration of the magnon group velocity modification in the system. The group velocities are calculated explicitly for all propagating frequencies and spin wave incidence angles. The matching method is used with nearest neighbor ferromagnetic interactions to calculate the coherent transmission coefficients for magnons incident on the nanostructure boundaries. They are investigated for different nanostructure thickness over the entire propagating frequency range of the system, in order to calculate the heat transport across the nanostructure. The model is applied to a system of three Iron ferromagnetic atomic layers and Gadolinium integrated nanostructure. The thermal conductivities are numerically calculated for individual magnon modes of the system. The results yield an understanding of the relationship between the magnons thermal conductivity of the system and the structural configuration of the integrated nanostructure.