An expression for the microwave power generated by a spin-torque oscillator in the presence of thermal noise is derived. This expression, when used in a subcritical regime, demonstrates that generated power is determined by the noise level and provides a simple way to experimentally determine the threshold current for microwave generation. The same expression gives a good quantitative description of the experimentally measured dependence of the generated power on the bias current in a moderate super-critical range of bias current variation.
@article{arxiv.0709.4553,
title = {Microwave power generated by a spin-torque oscillator in the presence of noise},
author = {Vasil Tiberkevich and Joo-Von Kim and Andrei Slavin},
journal= {arXiv preprint arXiv:0709.4553},
year = {2009}
}