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.

arXiv comment28 Pages, 11 Figures

References in corpus (17)

• Thermally assisted magnetization reversal in the presence of a spin-transfer torque
• 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
• Temperature dependence of spin-transfer-induced switching of nanomagnets
• Current-driven microwave oscillations in current perpendicular-to-plane spin-valve nanopillars
• Mechanisms limiting the coherence time of spontaneous magnetic oscillations driven by DC spin-polarized currents
• Microwave power generated by a spin-torque oscillator in the presence of noise
• Parametric excitation of a magnetic nanocontact by a microwave field
• Thermally-Assisted Spin-Transfer Torque Dynamics in Energy Space
• Spin torque switching of an in-plane magnetized system in a thermally activated region
• Averaged equation for energy diffusion on a graph reveals bifurcation diagram and thermally assisted reversal times in spin-torque driven nanomagnets
• Temperature dependence of the emission linewidth in MgO-based spin torque nano-oscillators
• Linewidth of Power Spectrum Originated from Thermal Noise in Spin Torque Oscillator
• Thermally-Assisted Spin-Transfer Torque Magnetization Reversal of Uniaxial Nanomagnets in Energy Space
• Optimization of spin-torque switching using AC and DC pulses

Cited by in corpus (17)

• Instability analysis of spin torque oscillator with an in-plane magnetized free layer and a perpendicularly magnetized pinned layer
• Magnetization switching by current and microwaves
• 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
• Stable oscillation in spin torque oscillator excited by a small in-plane magnetic field
• Bipolar switching in an orthogonal spin transfer spin valve device
• Current-induced Pinwheel Oscillations in Perpendicular Magnetic Anisotropy Spin Valve Nanopillars
• Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque
• Large Fluctuations and Singular Behavior of Nonequilibrium Systems
• Reliable spin-transfer torque driven precessional magnetization reversal with an adiabatically decaying pulse
• Zero-field dynamics stabilized by in-plane shape anisotropy in MgO-based spin-torque oscillators
• Damping dependence of spin-torque effects in thermally assisted magnetization reversal
• A reduced model for precessional switching of thin-film nanomagnets under the influence of spin-torque
• Switching time of spin-torque-driven magnetization in biaxial ferromagnets
• Modeling the computer memory based on the ferromagnet/superconductor multilayers