Frequency shift keying in vortex-based spin torque oscillators

Abstract

Vortex-based spin-torque oscillators can be made from extended spin valves connected to an electrical nanocontact. We study the implementation of frequency shift keying modulation in these oscillators. Upon a square modulation of the current in the 10 MHz range, the vortex frequency follows the current command, with easy identification of the two swapping frequencies in the spectral measurements. The frequency distribution of the output power can be accounted for by convolution transformations of the dc current vortex waveform, and the current modulation. Modeling indicates that the frequency transitions are phase coherent and last less than 25 ns. Complementing the multi-octave tunability and first-class agility, the capability of frequency shift keying modulation is an additional milestone for the implementation of vortex-based oscillators in RF circuit.

6 pages, 5 figures

References in corpus (3)

• Current-driven vortex oscillations in metallic nanocontacts
• Time domain measurement of phase noise in a spin torque oscillator
• Agility of vortex-based nanocontact spin torque oscillators

Cited by in corpus (8)

• Faster, farther, stronger: spin transfer torque driven high order propagating spin waves in nano-contact magnetic tunnel junctions
• Frequency shift keying by current modulation in a MTJ-based STNO with high data rate
• Analog and digital phase modulation of spin torque nano-oscillators
• Temperature dependence of linewidth in nano-contact based spin torque oscillators: effect of multiple oscillatory modes
• Super-harmonic injection locking of nano-contact spin-torque vortex oscillators
• Improved spectral stability in spin transfer nano-oscillators: single vortex versus coupled vortices dynamics
• Modulation and phase-locking in nanocontact vortex oscillators
• Mutual synchronization in spin torque and spin Hall nano-oscillators