Magnon instability driven by heat current in magnetic bilayers

  title={Magnon instability driven by heat current in magnetic bilayers},
  author={Yuichi Ohnuma and Hiroto Adachi and Eiji Saitoh and Sadamichi Maekawa},
  journal={Physical Review B},
We theoretically demonstrate that, in a ferromagnet/paramagnet bilayer, a magnon instability accompanied by a gigahertz microwave emission can be driven simply by means of a temperature bias. Employing many-body theory for investigating the effects of a phonon heat current on the magnon lifetime, we show that the magnon instability occurs upon the suppression of the Umklapp scattering at low temperatures, leading to microwave emission. The present finding provides crucial information about the… Expand

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