Propagation of Spin-Wave Packets in Individual Nanosized Yttrium Iron Garnet Magnonic Conduits.

Björn Heinz,David Breitbach,Philipp Pirro,Thomas Brächer,Steffen Steinert,Carsten Dubs,Andrii V Chumak,Bert Lägel,Thomas Meyer,Martin Kewenig,Anna M Friedel,Michael Schneider,Qi Wang

doi:10.1021/acs.nanolett.0c00657

Abstract

Modern-day CMOS-based computation technology is reaching its fundamental limitations. The emerging field of magnonics, which utilizes spin waves for data transport and processing, proposes a promising path to overcome these limitations. Different devices have been demonstrated recently on the macro- and microscale, but the feasibility of the magnonics approach essentially relies on the scalability of the structure feature size down to the extent of a few 10 nm, which are typical sizes for the established CMOS technology. Here, we present a study of propagating spin-wave packets in individual yttrium iron garnet (YIG) conduits with lateral dimensions down to 50 nm. Space and time-resolved microfocused Brillouin-light-scattering (BLS) spectroscopy is used to characterize the YIG nanostructures and measure the spin-wave decay length and group velocity directly. The revealed magnon transport at the scale comparable to the scale of CMOS proves the general feasibility of magnon-based data processing.

Highlights

Modern-day CMOS-based computation technology is reaching its fundamental limitations
To allow for further progress, the field of spintronics aims to complement CMOS by taking advantage of the spin degree of freedom to generate and control charge currents.[2]
A different approach to tackle these challenges and avoid electric currents can be found in the field of magnonics, which proposes a wave-based logic for more-than-Moore computing by utilizing spin waves to carry the information instead of electrons.[3−6] The phase of a spin wave offers an additional degree of freedom enabling efficient computing concepts, which typically rely on the interference of coherent spin waves

Summary

Methods

Additional figures, experimental details, and theoretical calculations; VNA-FMR characterization of the YIG film in use; detailed description and depiction of the nanostructuring procedure; the calculated inverse effective width; comparison of thermal BLS spectra for different waveguide widths and degradation of the first PSSW mode intensity; theoretical calculations and underlying equations of the spin-wave dispersion; calculation of the antennas far field; discussion of the spin-wave lifetime in nanoconduits; theoretical calculation and discussion of the nonlinear coefficient Tk; the frequency mismatch of the measured and calculated spin-wave spectra; definition of the potential circuit complexity; description of the time-resolved group velocity measurements and exemplary measurement for w = 1000 nm; influence of the applied laser power (PDF). All authors contributed to the scientific discussion and commented on the manuscript

■ ACKNOWLEDGMENTS

■ REFERENCES