Spin Torque Oscillators with Thermal Noise: A Constant Energy Orbit Approach

Abstract

We consider a biaxial macrospin with an easy and hard axis, and study its dynamical evolution under the combined effects of thermal noise and spin transfer torque. The spin-torque is associated with both a perpendicularly magnetized polarizer and an in-plane magnetized reference layer, leading to an effective tilt between the easy and spin polarization axes. Using techniques based on energy averaging over the relevant dynamical trajectories, we analyze the effects of tilt on the dynamics and derive the conditions for the occurrence of stable out-of-plane precessionary states. The presence of these states and their predicted stability boundaries can be tested in experiments on orthogonal spin-transfer devices, and may also serve as a test of the applicability of the macrospin model to real devices, which have internal magnetic degrees of freedom.

28 Pages, 11 Figures

References in corpus (8)

• State-dependent diffusion: thermodynamic consistency and its path integral formulation
• Generation linewidth of an auto-oscillator with a nonlinear frequency shift: Spin-torque nano-oscillator
• Spin-torque switching: Fokker-Planck rate calculation
• Spin-transfer pulse switching: From the dynamic to the thermally activated regime
• Current-driven microwave oscillations in current perpendicular-to-plane spin-valve nanopillars
• Microwave power generated by a spin-torque oscillator in the presence of noise
• Spin torque switching of an in-plane magnetized system in a thermally activated region
• Linewidth of Power Spectrum Originated from Thermal Noise in Spin Torque Oscillator

Cited by in corpus (7)

• Nonlinear analysis of magnetization dynamics excited by spin Hall effect
• Relaxation time and critical slowing down of a spin-torque oscillator
• A Perspective on Electrical Generation of Spin Current for Magnetic Random Access Memories
• Dynamic coupling of ferromagnets via spin Hall magnetoresistance
• Bipolar switching in an orthogonal spin transfer spin valve device
• Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque
• Modeling the computer memory based on the ferromagnet/superconductor multilayers