Time Domain Mapping of Spin Torque Oscillator Effective Energy

Abstract

Stochastic dynamics of spin torque oscillators (STOs) can be described in terms of magnetization drift and diffusion over a current-dependent effective energy surface given by the Fokker-Planck equation. Here we present a method that directly probes this effective energy surface via time-resolved measurements of the microwave voltage generated by a STO. We show that the effective energy approach provides a simple recipe for predicting spectral line widths and line shapes near the generation threshold. Our time domain technique also accurately measures the field-like component of spin torque in a wide range of the voltage bias values.

5 pages, 3 figures. Supplement included: 7 pages, 6 figures

References in corpus (8)

• Spin Transfer Torques
• Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices
• Spin-transfer-driven ferromagnetic resonance of individual nanomagnets
• Voltage-Induced Ferromagnetic Resonance in Magnetic Tunnel Junctions
• Generation linewidth of an auto-oscillator with a nonlinear frequency shift: Spin-torque nano-oscillator
• Lineshape distortion in a nonlinear auto-oscillator near generation threshold: Application to spin-torque nano-oscillators
• Microwave power generated by a spin-torque oscillator in the presence of noise
• Decoherence and mode-hopping in a magnetic tunnel junction-based spin-torque oscillator

Cited by in corpus (7)

• Nanowire Spin Torque Oscillator Driven by Spin Orbit Torques
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• Nonlinear behavior and mode coupling in spin transfer nano-oscillators
• Controlled spin-torque driven domain wall motion using staggered magnetic nanowires
• Magnetic phase transitions in Ta/CoFeB/MgO multilayers
• Dimensional crossover in spin Hall oscillators
• Comprehensive and Macrospin-Based Magnetic Tunnel Junction Spin Torque Oscillator Model - Part II: Verilog-A Model Implementation