title: Spin-wave-beam driven synchronization of nanocontact spin-torque oscillators.
abstract: The synchronization of multiple nanocontact spin-torque oscillators (NC-STOs) is mediated by propagating spin waves (SWs). Although it has been shown that the Oersted field generated in the vicinity of the NC can dramatically alter the emission pattern of SWs, its role in the synchronization behaviour of multiple NCs has not been considered so far. Here we investigate the synchronization behaviour in multiple NC-STOs oriented either vertically or horizontally, with respect to the in-plane component of the external field. Synchronization is promoted (impeded) by the Oersted field landscape when the NCs are oriented vertically (horizontally) due to the highly anisotropic SW propagation. Not only is robust synchronization between two oscillators observed for separations larger than 1,000 nm, but synchronization of up to five oscillators, a new record, has been observed in the vertical array geometry. Furthermore, the synchronization can no longer be considered mutual in nature.
authors.affiliation: Physics Department, University of Gothenburg, Gothenburg 412 96, Sweden.|NanOsc AB, Kista 164 40, Sweden.
authors.forename: A
authors.identifier: http://orcid.org/0000-0001-9619-7933
authors.initials: A
authors.lastname: Houshang
authors.affiliation: Physics Department, University of Gothenburg, Gothenburg 412 96, Sweden.|NanOsc AB, Kista 164 40, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Iacocca
authors.affiliation: Physics Department, University of Gothenburg, Gothenburg 412 96, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Dürrenfeld
authors.affiliation: Material Physics, School of ICT, Royal Institute of Technology, Electrum 229, Kista 164 40, Sweden.
authors.forename: S R
authors.initials: SR
authors.lastname: Sani
authors.affiliation: Physics Department, University of Gothenburg, Gothenburg 412 96, Sweden.|NanOsc AB, Kista 164 40, Sweden.|Material Physics, School of ICT, Royal Institute of Technology, Electrum 229, Kista 164 40, Sweden.
authors.forename: J
authors.identifier: http://orcid.org/0000-0002-3513-6608
authors.initials: J
authors.lastname: Åkerman
authors.affiliation: Physics Department, University of Gothenburg, Gothenburg 412 96, Sweden.|NanOsc AB, Kista 164 40, Sweden.
authors.forename: R K
authors.initials: RK
authors.lastname: Dumas