Spin current pumped by confined breathing skyrmion

Abstract

Spin pumping is a widely recognized method to generate the spin current in the spintronics, which can be found in varieties of magnetic materials and is acknowledged as a fundamentally dynamic process equivalent to the spin-transfer torque. In this work, we theoretically verified the oscillating spin current mixed by AC and DC components can be pumped from the microwave-motivated breathing skyrmion. The spin current can be pumped within a relatively low-frequency microwave compared with the in-plane ferromagnetic resonance (FMR). Although the amplitude of spin current density for a single confined skyrmion is several times lower than the FMR spin pumping, the pumped current would be improved to be the same order as the FMR through a tight skyrmion lattice. Based on the spin pumping of breathing skyrmion, we designed a high reading-speed racetrack memory model whose reading speed is much higher than the SOT (spin-orbit torque)/STT (spin-transfer torque) skyrmion racetrack. Our work focuses on the spin pumping phenomenon inside the breathing skyrmion, and it may contribute to the applications of the skyrmion-based device.

Strain Modulation of Magnonic Frequency Comb by Magnon–Skyrmion Interaction in Ferromagnetic Materials

“…To realize the dynamic regulation of skyrmion eigenmodes, different approaches have been adopted such as in‐plane magnetic fields, [ 35–37 ] spin‐polarized electric current, [ 38,39 ] temperature, [ 40 ] and current‐induced spin–orbit torque. [ 41–44 ] Due to the magnetoelastic coupling effect of ferromagnetic materials, mechanical control of magnetic order through strain [ 45 ] has also become a promising approach to modulate topological magnetic structures and regulate the dynamic responses of skyrmions in ferromagnetic materials. [ 46,47 ] For example, the uniaxial strain [ 48,49 ] and wavelike nonuniform strain [ 50 ] can modulate the skyrmion phase transitions in ferromagnetic thin films.…”

Chiral phenomena in magnetic multilayers

“…It is written together with Joren Harms who was actively involved in the analytical calculations and Patrick van Dieten who was actively involved in the numerical magnon mode calculations. croscopy [101], Lorentz transmission electron microscopy (LTEM) [41,102,103] and microwave response measured by a ferromagnetic resonance (FMR) spectrometer [104][105][106]. An FMR measurement is especially attractive as it is relatively simple and its theoretical understanding requires the computation of the collective modes of the system.…”