Online Spintronics Seminar #15: Aurélien Manchon

Modeling Spin-Orbit Phenomena at Magnetic Interfaces

Abstract:

Magnetic materials lacking inversion symmetry constitute a unique platform for the exploration and control of magnetism [1]. In these systems, typically multilayers of transition metal ferromagnets and heavy metals (W, Pt, Bi2Se3, etc.), interfacial spin-orbit coupling promotes a wealth of physical phenomena, among which the emergence of magnetic skyrmions (topological magnetic textures), spin-orbit torques (an efficient means to electrically control magnetization dynamics), as well as chiral magnetic damping (energy dissipation that depends on the texture chirality). While most of the initial theoretical progress has been achieved using minimal models (e.g., the Rashba two-dimensional gas), we have recently developed a multi-orbital tight-binding model of such heterostructures that enables us to model these various phenomena on equal footing and in a transparent manner [2,3]. In this presentation, based on the results of this model, I will investigate various aspects of the interplay between spin transport and magnetization dynamics mediated by spin-orbit coupling in chiral magnets. I will first discuss the orbital nature of interfacial spin-orbit coupling in magnetic multilayers and examine how it facilitates the onset of chiral magnetic textures. I will then present the physics of spin-orbit torques, their general features in metals and topological insulators, and inspect their relation to chiral magnetic properties such as Dzyaloshinskii-Moriya interaction and chiral magnetic damping. Finally, I will discuss the current-driven dynamics of magnetic skyrmions and propose various strategies to enhance their mobility, exploiting topological spin currents flowing through the texture [4].

[1] A. Manchon et al., arXiv:1801.09636; Rev. Mod. Phys. 91, 035004 (2019).
[2] S. Ghosh and A. Manchon, Phys. Rev. B 97, 134402 (2018); 100, 014412 (2019).
[3] G. Manchon, S. Ghosh, A. Manchon, submitted.
[4] A. Abbout, J. Weston, X. Waintal, A. Manchon, Phys. Rev. Lett. 121, 257203 (2018).

[saharsoumeeh]

why the bottom chain do not hybrid with each other? have you assumed that the atoms are far from each other?