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Register a new userTuning edge localized spin waves in magnetic microstripes by proximate magnetic structures
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The propagation of edge localized spin waves (E-SWs) in yttrium iron garnet (YIG) microstripes with/without the proximate magnetic microstructures is investigated by micromagnetic simulations. A splitting of the dispersion curve with the presence of permalloy (Py) stripe is also observed. The E-SWs on the two edges of YIG stripe have different wavelengths, group velocities, and decay lengths at the same frequencies. The role of the Py stripe was found to be the source of the inhomogeneous static dipolar field without dynamic coupling with YIG. This work opens new perspectives for the design of innovative SW interference-based logic devices.
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Spin excitations of magnetic thin films are the founding element for novel transport concepts in spintronics, magnonics, and magnetic devices in general. While spin dynamics have been extensively studied in bulk materials, their behaviour in mesoscopic films is less known due to experimental limitations. Here, we employ Resonant Inelastic X-Ray Scattering to investigate the spin excitation spectrum in mesoscopic Fe films, from bulk-like down to 3 unit cells thick. In bulk-like samples, we find isotropic, dispersive ferromagnons consistent with the dispersion observed by neutron scattering in bulk single crystals. As the thickness is reduced, these ferromagnons survive and evolve anisotropically: renormalising to lower energies along the out-of-plane direction while retaining their dispersion in the in-plane direction. This thickness dependence is captured by simple Heisenberg model calculations accounting for the confinement in the out-of-plane direction through the loss of Fe bonds. Our findings highlight the effects of mesoscopic scaling on spin dynamics and identify thickness as a knob for fine-tuning and controlling magnetic properties in films.
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We show that direct current in a tantalum microstrip can induce steady-state magnetic oscillations in an adjacent nanomagnet through spin torque from the spin Hall effect (SHE). The oscillations are detected electrically via a magnetic tunnel junction (MTJ) contacting the nanomagnet. The oscillation frequency can be controlled using the MTJ bias to tune the magnetic anisotropy. In this 3-terminal device the SHE torque and the MTJ bias therefore provide independent controls of the oscillation amplitude and frequency, enabling new approaches for developing tunable spin torque nano-oscillators.
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