We study the current controlled modulation of a nano-contact spin torque oscillator. Three principally different cases of frequency non-linearity (d2f/dIdc2 being zero, positive, and negative) are investigated. Standard non-linear frequency modulation theory is able to accurately describe the frequency shifts during modulation. However, the power of the modulated sidebands only agrees with calculations based on a recent theory of combined non-linear frequency and amplitude modulation.
@article{arxiv.0910.2819,
title = {Non-linear frequency and amplitude modulation of a nano-contact spin torque oscillator},
author = {P. K. Muduli and Ye. Pogoryelov and S. Bonetti and G. Consolo and Fred Mancoff and Johan Åkerman},
journal= {arXiv preprint arXiv:0910.2819},
year = {2015}
}