Microwave Signal Generation in Single-Layer Nano-Contact Spin Torque Oscillators
2013 (English)In: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 49, no 7, 4331-4334 p.Article in journal (Refereed) Published
We demonstrate spin transfer torque (STT) driven microwave signal generation, from about 250 MHz to above 3 GHz, in single perm alloy layers underneath a nano-contact with diameter of 100 nm. The threshold current for signal generation is found to be strongly hysteretic, the microwave signal shows a number of harmonics, zero-field operation is straightforward, and the microwave frequency increases quasi-linearly with drive current. All observations are consistent with STT driven motion of a vortex-antivortex pair nucleated by the Oersted field underneath the nano-contact. While the generated power is about 10 dB smaller than the best GMR based nano-contact spin torque oscillators, the linewidth of 6-100 MHz is of the same order.
Place, publisher, year, edition, pages
2013. Vol. 49, no 7, 4331-4334 p.
Single layer, spin torque oscillator, vortex
IdentifiersURN: urn:nbn:se:kth:diva-122702DOI: 10.1109/TMAG.2013.2250931ISI: 000322483200318ScopusID: 2-s2.0-84880810559OAI: oai:DiVA.org:kth-122702DiVA: diva2:623392
FunderSwedish Foundation for Strategic Research Swedish Research CouncilKnut and Alice Wallenberg Foundation
QC 20130910. Updated from accepted to published.2013-05-272013-05-272013-09-10Bibliographically approved