Effect of current-induced magnetic field on magnetization dynamics in spin-torque nano-oscillator with point-contact geometry

We show micromagnetic simulation results for spin-torque nano-oscillator (STNO) with point-contact geometry. Numerical results obtained from three different models are compared in order to investigate the effect of current-induced Oersted field and non-uniform current distribution on the characteristics of STNO. It is found that the Oersted field and non-uniform current distribution affect the frequency and precession mode both qualitatively and quantitatively. An anisotropic emission of spin-waves is observed only when considering the Oersted field properly. Our results suggest that a realistic consideration of the current distribution and consequent Oersted field distribution is of critical important to design STNOs and to understand the characteristics of STNOs. (C) 2013 Elsevier B. V. All rights reserved.