arXiv subjects

Q. Mistral

Publications and source records attributed to Q. Mistral.

3 recordsLinked to original sources

arXiv2007

Lineshape distortion in a nonlinear auto-oscillator near generation threshold: Application to spin-torque nano-oscillators

The lineshape in an auto-oscillator with a large nonlinear frequency shift in the presence of thermal noise is calculated. Near the generation threshold, this lineshape becomes strongly non-Lorentzian, broadened, and asymmetric. A Lorentzian lineshape is recovered far below and far above threshold, which suggests that lineshape distortions provide a signature of the generation threshold. The theory developed adequately describes the observed behavior of a strongly nonlinear spin-torque nano-oscillator.

cond-mat.mtrl-sci↗

arXiv2007

Current-driven vortex oscillations in metallic nanocontacts

We present experimental evidence of sub-GHz spin-transfer oscillations in metallic nano-contacts that are due to the translational motion of a magnetic vortex. The vortex is shown to execute large-amplitude orbital motion outside the contact region. Good agreement with analytical theory and micromagnetics simulations is found.

cond-mat.mtrl-sci↗

arXiv2006

Current-driven microwave oscillations in current perpendicular-to-plane spin-valve nanopillars

We study the current and temperature dependences of the microwave voltage emission of spin-valve nanopillars subjected to an in-plane magnetic field and a perpendicular-to-plane current. Despite the complex multilayer geometry, clear microwave emission is shown to be possible and spectral lines as narrow as 3.8 MHz (at 150 K) are observed.

cond-mat.mtrl-sci↗