Experimental test of an analytical theory of spin-torque-oscillator dynamics

Abstract

We make measurements of power spectral density of the microwave voltage emitted by a spin-torque-nano-oscillator (STNO) consisting of a ${\text{Ni}}_{86}{\text{Fe}}_{14}$ nanowire free layer and a ${\text{Co}}_{50}{\text{Fe}}_{50}$ nanomagnet fixed layer and compare our experimental results to predictions of an analytical theory of a single-mode STNO dynamics [Tiberkevich et al., Phys. Rev. B 78, 092401 (2008)]. We find that a complete set of the oscillator spectral properties---power, frequency, spectral linewidth, and line shape as functions of current---is self-consistently described by the analytical theory for moderate amplitudes of oscillations $(\ensuremath{\lesssim}70\ifmmode^\circ\else\textdegree\fi{})$ of the free-layer magnetization.