Nonlocal magnon-polaron transport in yttrium iron garnet

L. J. Cornelissen*, K. Oyanagi, T. Kikkawa, Z. Qiu, T. Kuschel, G. E. W. Bauer, B. J. van Wees, E. Saitoh

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

44 Citaten (Scopus)
240 Downloads (Pure)

Samenvatting

The spin Seebeck effect (SSE) is observed in magnetic insulator vertical bar heavy metal bilayers as an inverse spin Hall effect voltage under a temperature gradient. The SSE can be detected nonlocally as well, viz. in terms of the voltage in a second metallic contact (detector) on the magnetic film, spatially separated from the first contact that is used to apply the temperature bias (injector). Magnon-polarons are hybridized lattice and spin waves in magnetic materials, generated by the magnetoelastic interaction. Kikkawa et al. [Phys. Rev. Lett. 117, 207203 (2016)] interpreted a resonant enhancement of the local SSE in yttrium iron garnet (YIG) as a function of the magnetic field in terms of magnon-polaron formation. Here we report the observation of magnon-polarons in nonlocal magnon spin injection/detection devices for various injector-detector spacings and sample temperatures. Unexpectedly, we find that the magnon-polaron resonances can suppress rather than enhance the nonlocal SSE. Using finite element modeling, we explain our observations as a competition between the SSE and spin diffusion in YIG. These results give unprecedented insights into the magnon-phonon interaction in a keymagnetic material.

Originele taal-2English
Artikelnummer104441
Aantal pagina's14
TijdschriftPhysical Review B
Volume96
Nummer van het tijdschrift10
DOI's
StatusPublished - 29-sep-2017

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