Mode-hopping mechanism generating colored noise in a magnetic tunnel junction based spin torque oscillator
2014 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 105, no 13, 132404- p.Article in journal (Refereed) Published
The frequency noise spectrum of a magnetic tunnel junction based spin torque oscillator is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. We find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. These results indicate that the origin of 1/f frequency noise is related to mode-hopping, which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.
Place, publisher, year, edition, pages
2014. Vol. 105, no 13, 132404- p.
Colored noise, Magnetic tunnel junction, Mode-hopping, Spin-torque oscillators
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-155798DOI: 10.1063/1.4896634ISI: 000343031700038ScopusID: 2-s2.0-84907512845OAI: oai:DiVA.org:kth-155798DiVA: diva2:763351
FunderSwedish Foundation for Strategic Research Swedish Research CouncilKnut and Alice Wallenberg Foundation
QC 201411142014-11-142014-11-132014-11-14Bibliographically approved