Presentación3 magnetism

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    06-Sep-2015

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presentation about the magnetism course

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  • Omnidirectional spin-wave nanograting coupler

    Luis Lizardi

  • Metamaterials

    ! Photonic Crystals ! Light(photons)

    ! Magnonic Crystals ! Spin Waves(magnons)

    uNot be observed in the nature

    uPeriodic patterning at the nanoscale uControl!!

  • Magnonics and technology

    ! Current semiconductor technology

    ! SW in cellular nonlinear networks

    ! Low power consumption

    ! Source of short-wavelength SW

  • Some magnonic grating couplers

    Py nanowire(green) and CoFeB(blue) 1D Device

    Py(green) 2D Device

  • Some magnonic grating couplers

    Py thin film with Co nanodisks BGC

    CoFeB thin film with Py nanodisks BGC

  • and their specifications

    Con campo Sin campo

  • Evidence of grating-coupler modes

    ! Angular dependence spin-wave spectroscopy and back-folded dispersion relation

  • Evidence of grating-coupler modes

    ! Excitation spectrum I(k) of a BCG with a =800 nm in a in-plane field.

  • Evidence of grating-coupler modes

    ! Isofrequency lines in reciprocal space(photonics v/s SWs) Kalinikos, B. A. & Slavin, A. N. Theory of dipole-exchange spin wave spectrum for ferromagnetic films with mixed exchange boundary conditions. J. Phys. C Solid State Phys. 19, 70137033 (1986).

    o Pronounced anisotropy for SW o In-plane magnetic field H

  • Evidence of grating-coupler modes

    ! Angular dependence of spin-wave dispersion relations f(k)

  • SW emission in non high-symmetry directions

    ! Multidirectional SW detection for different BGCs

  • SWs for perpendicular magnetization

    ! 1.8 T applied perpendicular to the plane

    ! BGC with a = 800 nm

    ! Solid(dashed) arrows indicate resonance also seen in in-plane (only in out-og-plane)

  • Proposed device in magnon spintronic

  • Field dependent SW espectroscopy and SEM image of a BGC

  • Conclusions and Questions

    ! The NG method can be directly integrated on a chip

    ! Dont require electrical contacts to nanopillars

    ! Can generate plane wave with stable phase

    ! Works without restriction in both in-plane and out-of-plane fields(compared with NOs)

    ! The stable phase is relevant for operating CNNs