Magnon Mediated Domain Wall Heat Conductance in Ferromagnetic Wires

A theoretical study of magnon-mediated heat transport in electrically insulating 1D ferromagnetic wires containing a domain wall is presented. In the regime of validity of continuum micromagnetism a domain wall is found to have no effect on the heat conductance. However, spin waves are found to be reflected by domain walls with widths of a few lattice spacings, which is associated with emergence of an additional spin wave bound state. We also discuss the role of dipolar interactions in high dimensions to generalize the argument in our previous work. The resulting reduction of the heat conductance due to a DW should be significant for thin wires of Yttrium Iron Garnet with sharply defined magnetic domains.