title: Time domain mapping of spin torque oscillator effective energy.
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.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: Graham E
authors.initials: GE
authors.lastname: Rowlands
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Katine
authors.forename: Juergen
authors.initials: J
authors.lastname: Langer
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.forename: Ilya N
authors.initials: IN
authors.lastname: Krivorotov