Particle-like skyrmions interacting with a funnel obstacle

Abstract

The skyrmion-substrate interaction is an important issue to consider when studying particle-like skyrmions in nanostructures, which may strongly affect the skyrmion dynamics and lead to complex dynamic phenomena. Here, we report the current-driven dynamic behaviors of particle-like skyrmions interacting with the funnel obstacle in a ferromagnetic layer. We computationally demonstrate that a funnel obstacle with enhanced perpendicular magnetic anisotropy can be used to modify the dynamics of skyrmions due to the repulsive skyrmion-funnel interaction, which could generate several nontrivial effects, including the compression, clogging, annihilation, guided motion, and capturing of skyrmions. It is also found that the funnel obstacle can separate an incoming flow of skyrmions into two asymmetric flows. Moreover, we show that it is possible to capture skyrmions by the funnel obstacle in both static and dynamic ways. Our results are useful for understanding the skyrmion dynamics interacting with the substrate and could provide guidelines for the control of skyrmion flows in a transmission channel.

Dynamics of orbital skyrmions in a circular nanodisk

“…The steady speed v ts can be derived by solving eqn (5a) as follows: 20,37 v ts E p 2 uD sk /(aD) (6) where D C 2p(R sk /D + D/R sk ), and it is roughly equal to 4p. Then, the frequency f can be given by…”

“…Magnetic skyrmion, 1-3 a particle-like spin structure usually stabilized by Dzyaloshinskii-Moriya (DM) interaction, 4,5 has attracted much interest because of its rich physics [6][7][8] and possible implementations in various devices such as skyrmion diodes, 9,10 skyrmion ratchets, 11 racetrack memories, 12 logic gates, [13][14][15][16] and nano-oscillators. [17][18][19][20][21][22][23][24][25][26][27][28] Among them, nanooscillators based on skyrmions in circular nanodisks have been heavily studied because their high-frequency motion can be easily used for microwave generators and/or detectors.…”

Current-Induced Helicity Switching of Frustrated Skyrmions on a Square-Grid Obstacle Pattern

“…However, skyrmions could be destroyed by touching the edge. Recently, it has been shown that a more effective strategy to confine, protect, and control skyrmions in magnetic thin films is to construct defect lines with different magnetic properties [63][64][65][66][67][68][69][70][71][72][73][74] , which can be realized in engineered multilayer nanostructures 75) or by using focused irradiation 76) . However, the helicity dynamics of a frustrated skyrmion confined by defect lines have not yet been explored.…”

Chiral Skyrmions Interacting with Chiral Flowers

“…The square pattern is made of four obstacle bars, which are rectangle regions locally modified to have enhanced PMA K 0 . We assume that K 0 / K = 10 in order to make sure that the skyrmions cannot penetrate the obstacle boundary . Such a square pattern on the ferromagnetic substrate can, in principle, be fabricated in experiments. ,− The width of each obstacle bar is 10 nm, and the distance between two parallel inner edges of the square pattern is 100 nm.…”