Magnetic droplet nucleation boundary in orthogonal spin-torque nano-oscillators

Sunjae Chung, Anders Eklund, Ezio Iacocca, Seyed Majid Mohseni, Sohrab R. Sani, Lake Bookman, Mark A. Hoefer, Randy K. Dumas, Johan Akerman

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38 Citations (Scopus)
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Abstract

Static and dynamic magnetic solitons play a critical role in applied nanomagnetism. Magnetic droplets, a type of non-topological dissipative soliton, can be nucleated and sustained in nanocontact spin-torque oscillators with perpendicular magnetic anisotropy free layers. Here, we perform a detailed experimental determination of the full droplet nucleation boundary in the current–field plane for a wide range of nanocontact sizes and demonstrate its excellent agreement with an analytical expression originating from a stability analysis. Our results reconcile recent contradicting reports of the field dependence of the droplet nucleation. Furthermore, our analytical model both highlights the relation between the fixed layer material and the droplet nucleation current magnitude, and provides an accurate method to experimentally determine the spin transfer torque asymmetry of each device.
Original languageEnglish
Article number11209
JournalNature Communications
Volume7
Early online date18 Apr 2016
DOIs
Publication statusPublished - Sep 2016
Externally publishedYes

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