Abstract

Spin waves offer intriguing perspectives for computing and signal processing, because their damping can be lower than the ohmic losses in conventional complementary metal–oxide–semiconductor (CMOS) circuits. Magnetic domain walls show considerable potential as magnonic waveguides for on-chip control of the spatial extent and propagation of spin waves. However, low-loss guidance of spin waves with nanoscale wavelengths and around angled tracks remains to be shown. Here, we demonstrate spin wave control using natural anisotropic features of magnetic order in an interlayer exchange-coupled ferromagnetic bilayer. We employ scanning transmission X-ray microscopy to image the generation of spin waves and their propagation across distances exceeding multiples of the wavelength. Spin waves propagate in extended planar geometries as well as along straight or curved one-dimensional domain walls. We observe wavelengths between 1 μm and 150 nm, with excitation frequencies ranging from 250 MHz to 3 GHz. Our results show routes towards the practical implementation of magnonic waveguides in the form of domain walls in future spin wave logic and computational circuits.

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Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.

Additional information

Journal peer review information Nature Nanotechnology thanks Ferran Macià, Takuya Satoh and other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Acknowledgements

The authors thank B. Sarafimov, B. Watts and M. Bechtel for experimental support at the STXM beamlines, as well as C. Fowley, K. Kirsch, B. Scheumann and C. Neisser for their help with sample fabrication. Most of the experiments were performed at the Maxymus endstation at BESSY2, HZB, Berlin, Germany. The authors thank HZB for the allocation of synchrotron radiation beamtime. Some experiments were performed at the PolLux endstation at SLS, PSI, Villigen, Switzerland. Pollux is financed by BMBF via contracts 05KS4WE1/6 and 05KS7WE1. Support by the Nanofabrication Facilities Rossendorf at IBC, HZDR, Dresden, Germany is gratefully acknowledged. V.S. and A.D. acknowledge funding from the Helmholtz Young Investigator Initiative under grant VH-N6-1048. R.A.G. acknowledges financial support from FONDECYT Iniciacion 11170736 and 1161403. A.R.M. acknowledges funding from FONDECYT 3170647; funding from the Basal Program for Centers of Excellence, grant FB0807 CEDENNA, CONICYT is also acknowledged. V.T. and A.S. acknowledge support from the US National Science Foundation under grants EFMA-1641989 and ECCS-1708982 and from the DARPA M3IC grant under contract no. W911-17-C-0031. S.W. acknowledges funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 290605 (PSI-FELLOW/COFUND).

Author information

Author notes

    • Tobias Warnatz

    Present address: Uppsala Universitet, Uppsala, Sweden

Affiliations

  1. Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany

    • Volker Sluka
    • , Tobias Schneider
    • , Attila Kákay
    • , Tobias Warnatz
    • , Artur Erbe
    • , Alina Deac
    • , Jürgen Lindner
    • , Jürgen Fassbender
    •  & Sebastian Wintz
  2. Universidad Técnica Federico Santa María, Valparaíso, Chile

    • Rodolfo A. Gallardo
    •  & Pedro Landeros
  3. Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago, Chile

    • Rodolfo A. Gallardo
    •  & Pedro Landeros
  4. Max-Planck-Institut für Intelligente Systeme, Stuttgart, Germany

    • Markus Weigand
    •  & Gisela Schütz
  5. Leibniz Institut für Photonische Technologien, Jena, Germany

    • Roland Mattheis
  6. Universidad de Aysén, Coyhaique, Chile

    • Alejandro Roldán-Molina
  7. Oakland University, Rochester, MI, USA

    • Vasil Tiberkevich
    •  & Andrei Slavin
  8. Paul Scherrer Institut, Villigen, PSI, Switzerland

    • Jörg Raabe
    •  & Sebastian Wintz
  9. Technische Universität Dresden, Dresden, Germany

    • Jürgen Fassbender

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Contributions

S.W. conceived the experiment. V.S., M.W. and S.W. performed the STXM measurements. V.S. and S.W. analysed the data. T.S., T.W., A.K. and S.W. conducted the micromagnetic simulations. R.A.G., A.R.M. and P.L. calculated the spin wave dispersion relation. R.M. and S.W. supervised sample preparation. V.S. and S.W. wrote the manuscript. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding authors

Correspondence to Volker Sluka or Sebastian Wintz.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–3

  2. Supplementary Movie 1

    Plane and circular waves excited at 1.11 GHz, with left and right panels showing absolute and normalized contrast, respectively.

  3. Supplementary Movie 2

    Plane and circular waves excited at 1.46 GHz, with left and right panels showing absolute and normalized contrast, respectively.

  4. Supplementary Movie 3

    Plane and circular wave interference at the centre region for the different layers NiFe (top), CoFeB (middle) and the cumulative signal of Fe (bottom), with left and right panels showing absolute and normalized contrast, respectively.

  5. Supplementary Movie 4

    Spin-waves in domain walls with absolute (left) and normalized (right) contrast at 500 MHz (top) and 250 MHz (bottom).

  6. Supplementary Movie 5

    Spin-waves in domain walls excited by a pulse, with absolute (left) and normalized (right) contrast.

  7. Supplementary Movie 6

    Spin wave packet traveling along a curved domain wall (normalized contrast).

  8. Supplementary Movie 7

    Micromagnetic simulation of spin waves in a domain wall (normalized contrast).

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DOI

https://doi.org/10.1038/s41565-019-0383-4