Microwave power generated by a spin-torque oscillator in the presence of noise

TL;DR

This paper derives an expression for microwave power in spin-torque oscillators affected by thermal noise, enabling better understanding and experimental determination of threshold currents.

Contribution

It introduces a new analytical expression linking thermal noise to microwave power, improving the understanding of spin-torque oscillator behavior.

Findings

Expression accurately predicts power dependence on bias current

Enables experimental determination of threshold current

Validates with experimental data in moderate super-critical range

Abstract

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.