Spin-transfer Torque and Topological Changes of Magnetic Textures

Alberto Verga (1, 2)

1 CPT - Centre de Physique Théorique - UMR 7332
2 CPT - E6 Nanophysique

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 tight-binding 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.

Domaines: Autre [cond-mat.other]

Alberto Verga. Spin-transfer Torque and Topological Changes of Magnetic Textures. Discontinuity, Nonlinearity, and Complexity, 2016, 5 (1), pp.19--24. ⟨10.5890/DNC.2016.03.003⟩. ⟨hal-01500449⟩