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arXiv · 1709.09857

Tuning domain wall velocity with Dzyaloshinskii-Moriya interaction

Fernando Ajejas·Viola Krizakova·Dayane de Souza Chaves·Jan Vogel·Paolo Perna·Ruben Guerrero·Adrian Gudin·Julio Camarero·Stefania Pizzini
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Abstract

We have studied a series of Pt/Co/M epitaxial trilayers, in which Co is sandwiched between Pt and a non magnetic layer M (Pt, Ir, Cu, Al). Using polar magneto-optical Kerr microscopy, we show that the field- induced domain wall speeds are strongly dependent on the nature of the top layer, they increase going from M=Pt to lighter top metallic overlayers, and can reach several 100 m/s for Pt/Co/Al. The DW dynamics is consistent with the presence of chiral Néel walls stabilized by interfacial Dzyaloshinskii-Moriya interaction (DMI) whose strength increases going from Pt to Al top layers. This is explained by the presence of DMI with opposite sign at the Pt/Co and Co/M interfaces, the latter increasing in strength going towards heavier atoms, possibly due to the increasing spin-orbit interaction. This work shows that in non-centrosymmetric trilayers the domain wall dynamics can be finely tuned by engineering the DMI strength, in view of efficient devices for logic and spitronics applications.

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Fernando Ajejas, Viola Krizakova, Dayane de Souza Chaves, Jan Vogel, Paolo Perna, Ruben Guerrero, Adrian Gudin, Julio Camarero, Stefania Pizzini. 2017-09-28. Tuning domain wall velocity with Dzyaloshinskii-Moriya interaction. https://doi.org/10.1063/1.5005798

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