Abstract
Spin-torque oscillators are strong candidates as nanoscale microwave generators and detectors. However, because of large amplitude-phase coupling (nonlinearity), phase noise is enhanced over other linear autooscillators. One way to reduce nonlinearity is to use ferromagnetic layers as a resonator and excite them at localized spots, making a resonator-excitor pair. We investigated the excitation of oscillations in dipole-coupled ferromagnetic layers, driven by localized current at ferromagnetic nanocontacts. Oscillations possessed properties of optical-mode spin waves and at low field (≈200 Oe) had high frequency (15 GHz), a moderate precession amplitude (2-3), and a narrow spectral linewidth (<3 MHz) due to localized excitation at nanocontacts. Micromagnetic simulation showed emission of the resonator's characteristic optical-mode spin waves from disturbances generated by domain-wall oscillations at nanocontacts.
Original language | English |
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Article number | 024408 |
Journal | Physical Review B |
Volume | 93 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2016 Jan 14 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics