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

摘要

We present the temperature dependence of the thermal magnon density in a thinferromagnetic layer. By employing Brillouin light scattering and varying thetemperature, an increase of the magnon density accompanied by a lowering of thespin-wave frequency is observed with increasing temperature. The magnon densityfollows the temperature according to the Bose-Einstein distribution functionwhich leads to an approximately linear dependency. In addition, the influenceof this effect in spin-transfer-torque-driven systems is presented. Inparticular, the increase in the magnon density with temperature sets the limitfor a suppression of magnons in charge current-driven systems. Hence, themaximum possible suppression of thermal magnons occurs at a finite current.