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Discontinuity, Nonlinearity, and Complexity 5(1) (2016) 19--24 | DOI:10.5890/DNC.2016.03.003

Alberto Verga

Aix-Marseille Université, IM2NP, Campus St Jerme, service 142, 13387 Marseille, France

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Abstract

The electric manipulation of magnetic textures in nanostructures, important for applications in spintronics, can be realized through the spin-transfer torque mechanism: a spin-polarized current can modify the magnetization of skyrmions and magnetic vortices, and eventually change the topology of the magnetization. The spin-transfer torque and the intrinsic space and time scales of the topological changes are essentially quantum mechanical. We model the interaction between itinerant and fixed spins with a simple tightbinding hamiltonian in a square lattice. The dynamics is described by the Schrödinger equation for the electrons and the Landau-Lifshitz equation for the evolution of the magnetic texture. We investigate the phenomenology of the topological change of a Belavin-Polyakov skyrmion under the action of a spin-polarized current and show that adding an exchange dissipation term, regularizes the transition towards a ferromagnetic state.

Acknowledgments

We thank R. G. Elias for useful discussions.

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