Domain wall heat conductance in ferromagnetic wires

TL;DR

This paper theoretically investigates heat transport in insulating ferromagnetic wires with domain walls, finding that while domain walls do not affect heat conductance in continuum models, spin wave reflections at narrow walls can significantly influence heat transfer in thin films.

Contribution

It reveals the impact of narrow domain walls on spin wave reflection and heat conductance, highlighting effects beyond continuum micromagnetism.

Findings

Domain walls have no effect on heat conductance in continuum models.

Narrow domain walls reflect spin waves and create bound states.

Heat conductance can be significant in thin YIG films with sharp domains.

Abstract

We present a theoretical study of heat transport in electrically insulating ferromagnetic wires containing a domain wall. 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. The resulting domain wall heat conductance should be significant for thin films of Yttrium Iron Garnet with sharply defined magnetic domains.