Spin-Wave-Mode Coexistence on the Nanoscale: A Consequence of the Oersted-Field-Induced Asymmetric Energy Landscape

Randy K. Dumas, E. Iacocca, S. Bonetti, S. R. Sani, S. M. Mohseni, A. Eklund, J. Persson, O. Heinonen, and Johan Åkerman

Phys. Rev. Lett. 110, 257202 – Published 18 June 2013

Abstract

It has been argued that if multiple spin wave modes are competing for the same centrally located energy source, as in a nanocontact spin torque oscillator, that only one mode should survive in the steady state. Here, the experimental conditions necessary for mode coexistence are explored. Mode coexistence is facilitated by the local field asymmetries induced by the spatially inhomogeneous Oersted field, which leads to a physical separation of the modes, and is further promoted by spin wave localization at reduced applied field angles. Finally, both simulation and experiment reveal a low frequency signal consistent with the intermodulation of two coexistent modes.

Received 11 March 2013

DOI:https://doi.org/10.1103/PhysRevLett.110.257202

Authors & Affiliations

Randy K. Dumas^1,*, E. Iacocca¹, S. Bonetti², S. R. Sani^3,4, S. M. Mohseni^3,4, A. Eklund⁵, J. Persson⁴, O. Heinonen^6,7, and Johan Åkerman^1,3,4

¹Physics Department, University of Gothenburg, 412 96 Gothenburg, Sweden
²Department of Physics, Stanford University, Stanford, California 94305, USA
³Materials Physics, School of ICT, Royal Institute of Technology (KTH), 164 40 Kista, Sweden
⁴NanOsc AB, Electrum 205, 164 40 Kista, Sweden
⁵Devices and Circuits, School of ICT, Royal Institute of Technology (KTH), 164 40 Kista, Sweden
⁶Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
⁷Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA