We investigated the possibilities of controlling the nonlinear frequency
shift of the magnetization oscillations in a spin-transfer nanoscillator by
varying the magnitude and direction of the bias magnetic field. We considered
both isotropic ferromagnetic materials and crystals with uniaxial and cubic
crystallographic anisotropies. We have shown that achieving a zero nonlinear
frequency shift is possible with a certain orientation of the bias magnetic
field vector. The results of the theoretical analysis based on the method of
Hamiltonian formalism are in good agreement with the micromagnetic simulations.
Our research reveals the way to control the frequency tuning of a spin transfer
nanoscillator, which is crucial for spintronic signal generation devices.Comment: 6 pages, 3 figure