Stochastic Magnetization Dynamics Excited by Spin-Polarized Current in Magnetic Nano-Structures

摘要

The work is devoted to theoretical research leading to the fundamental understanding of the influence of thermal noise on the performance of nano-sized spin-torque microwave oscillators for military and space applications. In contrast with the existing theories, the developed theory is not be based on the assumption that the noise power is much smaller than the power generated by the oscillator. The theory takes into account strong nonlinearity of nano-scale spin-torque magnetic devices, i.e. dependence of device parameters (frequency, damping rate, etc.) on the amplitude of the generated microwave oscillations. The developed theory lays foundation for the practical development of tunable nano-sized spin torque microwave oscillators. Such devices may be desirable in the future nano-electronic circuits designed for military and space-oriented applications. These devices could replace current semiconductor microwave generators, eliminating the sensitivity of such generators to ionizing radiation. This research does not include the areas of intentional interference (jamming/RF weapons), noise in space environment (radiation hardening), or other countermeasure related issues.