Intrinsic frequency doubling in a magnetic tunnel junction–based spin torque oscillator

We discuss the coherence of magnetic oscillations in a magnetic tunnel junction based spin torque oscillator as a function of the external field angle. Time-frequency analysis shows mode hopping between distinct oscillator modes, which arises from linear and nonlinear couplings in the Landau-Lifshitz-Gilbert equation, analogous to mode hopping observed in semiconductor ring lasers. These couplings and, therefore, mode hopping are minimized near the current threshold for the antiparallel alignment of free-layer with reference layer magnetization. Away from the antiparallel alignment, mode hopping limits oscillator coherence.

show abstract

“…and because closer to 180 • , the observed m 2 coherence time is limited by frequency doubling [11,16]. The plots in Fig.…”

Section: (B)]mentioning

confidence: 88%

Decoherence and Mode Hopping in a Magnetic Tunnel Junction Based Spin Torque Oscillator

2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…While the frequency can be increased using the magnetic field, the output power usually drops with increasing field strength; obtaining higher power at higher frequencies is thus a challenge. A novel method of achieving this involves frequency doubling in MTJ-STNOs [154]. In that work, powers of up to 1.25 nW were demonstrated at a frequency of ∼10 GHz.…”

Section: Functional Properties a Frequency Rangementioning

confidence: 99%

Spin-Torque and Spin-Hall Nano-Oscillators

et al. 2016

View full text Add to dashboard Cite

This paper reviews the state of the art in spin-torque and spin Hall effect driven nano-oscillators. After a brief introduction to the underlying physics, the authors discuss different implementations of these oscillators, their functional properties in terms of frequency range, output power, phase noise, and modulation rates, and their inherent propensity for mutual synchronization. Finally, the potential for these oscillators in a wide range of applications, from microwave signal sources and detectors to neuromorphic computation elements, is discussed together with the specific electronic circuitry that has so far been designed to harness this potential.

QS 2016

show abstract

“…Obviously, this gradient field can be used to trap the skyrmions. In addition, the gradient magnetic field may also be created by a superconducting vortex system [48,49] or circularly polarized laser technique [18,32,50,51].…”

Section: Trapping Multiple Skyrmionsmentioning

confidence: 99%