Global analysis of frequency modulation experiments in a vortex oscillator

• Frequency modulation is performed on a vortex oscillator.
• A method of global analysis of the whole set of data is described.
• The same four parameters account for all experimental curves.
• Frequency modulation and quasi-static experiment cannot be compared.
• Time scales involved with respect to vortex relaxation time must be considered.

Frequency modulation is performed on a vortex oscillator at various modulation frequencies and powers. A global analysis of the whole set of data is proposed, so that all experimental curves are described with the same four parameters. Three of these parameters describe the dependence of the instantaneous frequency with modulating current. This dependence appears significantly different from the frequency-current dependence observed in a quasi-static experiment. The discrepancy is ascribed to the different time scales involved, compared to the relaxation time of the vortex oscillator.