Efficient geometrical control of spin waves in microscopic YIG waveguides

Abstract

We study, experimentally and by micromagnetic simulations, the propagation of spin waves in 100-nm thick YIG waveguides, where the width linearly decreases from 2 to 0.5 μm over a transition region with varying lengths between 2.5 and 10 μm. We show that this geometry results in a downconversion of the wavelength, enabling efficient generation of waves with wavelengths down to 350 nm. We also find that this geometry leads to a modification in the group velocity, allowing for almost-dispersionless propagation of spin-wave pulses. Moreover, we demonstrate that the influence of energy concentration outweighs that of damping in these YIG waveguides, resulting in an overall increase in the spin-wave intensity during propagation in the transition region. These findings can be utilized to improve the efficiency and functionality of magnonic devices that use spin waves as an information carrier.

Spectrum evolution and chirping of laser-induced spin wave packets in thin iron films

“…To make the effect more prominent at smaller distances, it is possible to use magnonic crystals, multilayered structures, or their hybrids [43][44][45] with a high dispersion of the group velocity of SWs. On the flipside, the geometrical design of the waveguide paves the way to suppress the dispersion altogether 46,47 .…”

Tuning of Magnetic Damping in Y3Fe5O12/Metal Bilayers for Spin-Wave Conduit Termination

“…Up to now, the standard experimental approach has involved the use of elongated SW waveguides, usually with canted ends [27,28,35,36]. Moreover, a recent study showed that the SW intensity is well maintained in nanoscopic, tapered waveguides [37]. Following further miniaturization and an increased packing of SW devices, controlled SW damping will become important in limiting back reflection at open-ended or unused waveguide ports.…”