Spin Seebeck Effect in Helimagnetic Cu$_2$OSeO$_3$: Test of Bulk Magnon Spin Current Theory

ORAL

Abstract

Cu$_2$OSeO$_3$ exhibits$^a$ the largest magnon thermal conductivity of any known ferro- or ferrimagnet. Here we report temperature ($T$) and magnetic field-dependent measurements of magnon thermal conductivity ($\kappa_m$) and longitudinal spin Seebeck coefficient ($S_{LSSE}$) in 10-nm Pt/Cu$_2$OSeO$_3$ heterostructures for 1~K $\leq T\leq$~15~K. Measurements for three different specimens, having spin-mixing conductances that vary by more than an order of magnitude, demonstrate a relationship between $\kappa_m$ and $S_{LSSE}$ in good agreement with bulk magnon spin current theory.
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$^a$ N. Prasai {\it et al.}, Phys. Rev. B {\bf 95}, 224407 (2017).

*This material is based on work supported by the U.S. DOE, Off. of BES, Div. of Mater. Sci. and Eng., under grant No. DE-SC0008607 (UM). TMM was supported as part of the Institute for Quantum Matter, an Energy Frontier Research Center funded by the U.S. DOE, Off. of Sci., BES under Award No. DE-SC0019331. BAT acknowledges the NSF, Div. of Mater. Res., Sol. St. Chem., CAREER grant No. DMR-1253562. G.G.M. acknowledges generous support from the NSF-GRFP, Grant No. DGE-1232825.

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Presenters

  • Artem Akopyan

    • Physics, Univ of Miami

Authors

  • Artem Akopyan

    • Physics, Univ of Miami

  • Narayan Prasai

    • Physics, Univ of Miami

  • Benjamin Trump

    • Chemistry, Johns Hopkins Univ

  • Guy G. Marcus

    • Chemistry, Johns Hopkins Univ

  • Tyrel McQueen

    • Johns Hopkins University
    • Chemistry, Johns Hopkins Univ
    • Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University

  • Joshua Cohn

    • Physics, Univ of Miami