Jeudi 28 Avril à 14h00,
Salle Remy Lemaire, K223
Orateur : Jan Vogel (Institut Néel)
"Chiral domain walls and skyrmions in ultrathin magnetic films"
Abstract
In this seminar, I will show some recent results we have obtained on Pt/FM/Oxide stacks, where FM is an ultrathin layer (1nm or less) of a ferromagnetic metal (mainly cobalt). The structural inversion asymmetry of these stacks, together with the strong spin-orbit interaction of the Pt, gives rise to a Dzyaloshinskii-Moriya interaction which can lead to chiral spin structures in the FM layer. In particular, it induces chiral Néel domain walls with high stability, allowing to move them at high velocities using magnetic field or current pulses [1,2]. We have recently shown that these velocities can be further increased, up to several hundreds of m/s, by reducing the saturation magnetization of the FM layer [3]. In collaboration with Spintec, we also obtained the first direct magnetic images of isolated, room temperature magnetic skyrmions in Pt/Co/MgO stacks using high resolution synchrotron x-ray microscopy [4].
References
[1] T.A Moore et al., Appl. Phys. Lett. 93, 262504 (2008) ; I.M. Miron et al., Nature Mater. 10, 419 (2011).
[2] A. Thiaville et al., EPL (Europhysics Letters) 100, 57002 (2012).
[3] T.H. Pham et al., EPL (Europhysics Letters) 113, 67001 (2016).
[4] O. Boulle et al., Nature Nano., <10.1038/nnano.2015.315> (2016).