5 research outputs found
Noise properties of a resonance-type spin-torque microwave detector
We analyze performance of a resonance-type spin-torque microwave detector
(STMD) in the presence of noise and reveal two distinct regimes of STMD
operation. In the first (high-frequency) regime the minimum detectable
microwave power is limited by the low-frequency Johnson-Nyquist
noise and the signal-to-noise ratio (SNR) of STMD is proportional to the input
microwave power . In the second (low-frequency) regime is limited by the magnetic noise, and the SNR is proportional to
. The developed formalism can be used for the optimization
of the practical noise-handling parameters of a STMD.Comment: 3 pages, 2 figure
Simultaneous multitone microwave emission by dc-driven spintronic nano-element
International audienceCurrent-induced self-sustained magnetization oscillations in spin-torque nano-oscillators (STNOs) are promising candidates for ultra-agile microwave sources or detectors. While usually STNOs behave as a monochromatic source, we report here clear bimodal simultaneous emission of incommensurate microwave oscillations in the frequency range of 6 to 10 gigahertz at femtowatt level power. These two tones correspond to two parametrically coupled eigenmodes with tunable splitting. The emission range is crucially sensitive to the change in hybridization of the eigenmodes of free and fixed layers, for instance, through a slight tilt of the applied magnetic field from the normal of the nanopillar. Our experimental findings are supported both analytically and by micromagnetic simulations, which ascribe the process to four-magnon scattering between a pair of radially symmetric magnon modes and a pair of magnon modes with opposite azimuthal index. Our findings pave the way for enhanced cognitive telecommunications and neuromorphic systems that use frequency multiplexing to improve communication performance