Thermalization of hot electrons via interfacial electron-magnon interaction

Abstract

Recent work on layered structures of superconductors (S) or normal metals (N) in contact with ferromagnetic insulators (FI) has shown how the properties of the previous can be strongly affected by the magnetic proximity effect due to the static FI magnetization. Here we show that such structures can also exhibit a new electron thermalization mechanism due to the coupling of electrons with the dynamic magnetization, i.e., magnons in FI. We here study the heat flow between the two systems and find that in thin films the heat conductance due to the interfacial electron-magnon collisions can dominate over the well-known electron-phonon coupling below a certain characteristic temperature that can be straightforwardly reached with present-day experiments. We also study the role of the magnon band gap and the induced spin-splitting field induced in S on the resulting heat conductance and show that heat balance experiments can reveal information about such quantities in a way quite different from typical magnon spectroscopy experiments.

Magnonic spin Joule heating and rectification effects

“…The latter admit strong nonlinear effects since a new and small energy scale -the superconducting gap -determines properties such as quasiparticle density of states [34][35][36][37]. Recent years have seen an upsurge of activity in this context with several exciting phenomena discussed, experimentally [33,[38][39][40][41][42][43][44][45][46] as well as theoretically [35][36][37][47][48][49][50][51][52][53]. However, the possibility of transport influencing, and even destroying, the superconducting state was not considered.…”