Topological skyrmion dynamics driven by spin-transfer torque - Presentazione orale - Conferenza internazionale

Abstract

We show that in a spin-valve consisting of Pt(5 nm)/Co(0.6 nm)/Cu (4 nm)/CoPt(4 nm) a perpendicular spin current, in the presence of the DMI and strong perpendicular anisotropy, induces the rotation of the spins from the hedgehog-like to the vortex-like texture in the topological droplet state and excites low-frequency topological modes. A quantitative description of topological droplet modes is given according to an analytical model based on the linearization of the equations of motion including intrinsic positive Gilbert damping and negative damping related to the spin-transfer torque. The analytical frequency of the topological droplet mode is expressed as the solution of a second-order algebraic equation written in terms of the magnetic parameters including the intrinsic and extrinsic damping