Service de Physique de l'Etat Condensé

Spin wave and spintronic devices with YIG
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The recent discovery that spin angular momentum can be exchanged between the magnetization of an insulating ferromagnet and the conduction electrons of a normal metal layer has opened new perspectives [1]. In particular, it is now possible to incorporate materials such as YIG (Yttrium Iron Garnet, well known for its unsurpassed microwave properties) in innovative spintronic devices. Thanks to the recent progress in the growth of high quality, ultra-thin YIG films [2], electronic control of their relaxation obtained through pure spin currents generated by the spin Hall effect at the interface between a strong spin-orbit metal (e.g., Pt) and YIG might be possible.

Conversely, the spin current emitted by the magnetization precession can be used to probe the YIG dynamics [3,4]. This work is part of a new fruitful axis of research, "magnonics": the use spin waves (magnons) instead of electrons to transmit and process information. The idea is to nanopattern ultra-thin YIG films to take advantage of the specific properties of spin wave propagation in confined geometries and to propose new electronically controlled microwave devices. Magnetic Resonance Force Microscopy [5] is used to perform ferromagnetic resonance on magnetic nanostructures.

[1] Y. Kajiwara, et al., Transmission of electrical signals by spin-wave interconversion in a magnetic insulator. Nature 464, 262 (2010).

[2] O. d'Allivy Kelly, Hahn, et al., Inverse spin Hall effect in nanometer-thick Yttrium Iron Garnet/Pt system. Appl. Phys. Lett. 103,

082408 (2013).

[3] C. Hahn, et al., Comparative measurements of inverse spin Hall effects and magnetoresistance in YIG/Pt and YIG/Ta. Phys. Rev. B 87,

174417 (2013).

[4] C. Hahn, et al., Conduction of spin currents through insulating oxides. arXiv:1310.6000 (2013).

[5] B. Pigeau, C. Hahn, et. al., Measurement of the Dynamical Dipolar Coupling in a Pair of Magnetic Nanodisks Using a Ferromagnetic Resonance Force Microscope. Phys. Rev. Lett. 109, 247602 (2012)

 

Maj : 06/10/2015 (2268)

 

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