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Updated: May 8, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Time domain mapping of spin torque oscillator effective energy
Graham E Rowlands1, Jordan A Katine, Juergen Langer
1Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Abstract:
Stochastic dynamics of spin torque oscillators 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 spin torque oscillator. We show that the effective energy approach provides a simple recipe for predicting spectral linewidths and line shapes near the generation threshold. Our time domain technique also accurately measures the fieldlike component of spin torque in a wide range of the voltage bias values.
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