Micromagnetic Analysis of Nonlinear Dynamics in Spintronic Analog Modulators

• Published in: IEEE transactions on magnetics Vol. 45; no. 11; pp. 5239 - 5242
• Main Authors: Puliafito, V., Consolo, G., Lopez-Diaz, L., Azzerboni, B.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.11.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplitude modulation; Cross-disciplinary physics: materials science; rheology; Devices; Exact sciences and technology; Frequency modulation; Injection locking; Magnetic analysis; Magnetic devices; Magnetic domains; Magnetic modulators; Magnetism; Magnetization; Magnetoelectronics; Materials science; Micromagnetics; micromagnetism; Modulation; Modulators; Nanoscale devices; Nanostructure; Nonlinear dynamics; nonlinear modulation; Nonlinearity; Other topics in materials science; Phase modulation; Physics; Sidebands; spin-transfer oscillators; Injection locking; micromagnetism; nonlinear modulation; spin-transfer oscillators; Oscillators; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2009.2031085

The simultaneous action of dc and ac spin-polarized current traversing a magnetic nanocontact device results in a combined amplitude-frequency nonlinear modulation process, a promising application of spin-transfer oscillators. A micromagnetic analysis of the nonlinear magnetization dynamics occurring in such devices is carried out in both spatial and frequency domain. Numerical results show that the proposed combined modulation scheme affects the amplitude of the sidebands as well as their phase, and remark a substantial difference with respect to the properties exhibited by a classical linear modulator. Further investigations performed as function of the frequency of the modulating signal allow to establish that, when the modulating frequency approaches the carrier one, no modulation occurs and a frequency pulling, typical of injection locking phenomena, takes place instead.