Magnon currents excited by the spin Seebeck effect in ferromagnetic EuS thin films

Abstract

A magnetic insulator is an ideal platform to propagate spin information by exploiting magnon currents. However, until now, most studies have focused on Y${}_3$Fe${}_5$O${}_{12}$ (YIG) and a few other ferri- and antiferromagnetic insulators, but not on pure ferromagnets. In this study, we demonstrate for the first time that magnon currents can propagate in ferromagnetic insulating thin films of EuS. By performing both local and non-local transport measurements in 18-nm-thick films of EuS using Pt electrodes, we detect magnon currents arising from thermal generation by the spin Seebeck effect. By comparing the dependence of the local and non-local signals with the temperature (< 30 K) and magnetic field (< 9 T), we confirm the magnon transport origin of the non-local signal. Finally, we extract the magnon diffusion length in the EuS film (~140 nm), a short value in good correspondence with the large Gilbert damping measured in the same film.

17 pages, 5 figures, and Supplemental Material

References in corpus (16)

• Theory of spin Hall magnetoresistance
• Magnon transport in quasi-two-dimensional van der Waals antiferromagnets
• Spin Insulatronics
• Temperature dependence of the magnon spin diffusion length and magnon spin conductivity in the magnetic insulator yttrium iron garnet
• Revealing the magnetic proximity effect in EuS/Al bilayers through superconducting tunneling spectroscopy
• Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons
• Control of spin injection by direct current in lateral spin valves
• Long distance magnon transport in the van der Waals antiferromagnet CrPS${}_4$
• Control of nonlocal magnon spin transport via magnon drift currents
• Criteria for accurate determination of the magnon relaxation length from the nonlocal spin Seebeck effect
• Superconductor-ferromagnet hybrids for non-reciprocal electronics and detectors
• Lateral transport properties of thermally excited magnons in yttrium iron garnet films
• Local and nonlocal spin Seebeck effect in lateral Pt-$\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_3$-Pt devices at low temperatures
• Very large thermal rectification in ferromagnetic insulator-based superconducting tunnel junctions
• Magnetic field dependence of the nonlocal spin Seebeck effect in Pt/YIG/Pt systems at low temperatures
• Reconstruction of an effective magnon mean free path distribution from spin Seebeck measurements in thin films

Cited by in corpus (4)

• Electrical control of magnetism by electric field and current-induced torques
• Superconductor-ferromagnet hybrids for non-reciprocal electronics and detectors
• Magnon dispersion and spin transport in CrCl${}_3$ bilayers under different strain-induced magnetic states
• Unconventional magnon transport in antiferromagnet NiPS${}_3$ induced by an anisotropic spin-flop transition