Experimental investigation of the temperature-dependent magnon density and its influence on studies of spin-transfer-torque-driven systems

Thomas Meyer; Thomas Brächer; Frank Heussner; Alexander A. Serga; Hiroshi Naganuma; Koki Mukaiyama; Mikihiko Oogane; Yasuo Ando; Burkard Hillebrands; Philipp Pirro

arXiv · 1706.00619

Experimental investigation of the temperature-dependent magnon density and its influence on studies of spin-transfer-torque-driven systems

Thomas Meyer·Thomas Brächer·Frank Heussner·Alexander A. Serga·Hiroshi Naganuma·Koki Mukaiyama·Mikihiko Oogane·Yasuo Ando·Burkard Hillebrands·Philipp Pirro

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Abstract

We present the temperature dependence of the thermal magnon density in a thin ferromagnetic layer. By employing Brillouin light scattering and varying the temperature, an increase of the magnon density accompanied by a lowering of the spin-wave frequency is observed with increasing temperature. The magnon density follows the temperature according to the Bose-Einstein distribution function which leads to an approximately linear dependency. In addition, the influence of this effect in spin-transfer-torque-driven systems is presented. In particular, the increase in the magnon density with temperature sets the limit for a suppression of magnons in charge current-driven systems. Hence, the maximum possible suppression of thermal magnons occurs at a finite current.

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Thomas Meyer, Thomas Brächer, Frank Heussner, Alexander A. Serga, Hiroshi Naganuma, Koki Mukaiyama, Mikihiko Oogane, Yasuo Ando, Burkard Hillebrands, Philipp Pirro. 2017-06-02. Experimental investigation of the temperature-dependent magnon density and its influence on studies of spin-transfer-torque-driven systems. https://arxiv.org/abs/1706.00619

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