Bilayer skyrmion dynamics on a magnetic anisotropy gradient

Abstract

Magnetic skyrmion transport has been primarily based on the use of spin torques which require high current densities and face performance deterioration associated with Joule heating. In this work, we derive an analytical model for energy efficient skyrmion propagation in an antiferromagneticallycoupled bilayer structure using a magnetic anisotropy gradient. The interlayer skyrmion coupling provides a strong restoring force between the skyrmions, which not only prevents annihilation but also increases their forward velocity up to the order of km s -1 . For materials with low Gilbert damping parameter, the interlayer skyrmion coupling force can be amplified up to ten times, with a corresponding increase in velocity. Furthermore, the analytical model also provides insights into the dynamics of skyrmion pinning and relaxation of asymmetric skyrmion pairs in bilayer-coupled skyrmion systems.

Skyrmion battery effect via inhomogeneous magnetic anisotropy

“…In the presence of a carefully patterned anisotropy gradient [50][51][52] , a skyrmion driven by a voltage pulse can travel more than 500nm. An interlayer coupling in a synthetic antiferromagnetic bilayer structure with an anisotropy gradient can further enhance the skyrmion velocity 53 .…”

Temperature-modulated magnetic skyrmion phases and transformations analysis from first-order reversal curve study

“…A magnetic skyrmion is a particlelike nanoscale magnetization state [1][2][3][4][5]. With promising potential as high-density information carriers, magnetic skyrmions are now actively investigated for applications such as memory [1,4,[6][7][8], computational logic [9][10][11][12], and nonconventional computing systems [13][14][15][16][17][18][19]. Magnetic skyrmions stabilization requires the system to be favorable for nonparallel adjacent spins, which can be supported by the Dzyaloshinskii-Moriya interaction (DMI) [20][21][22] and dipolar interaction [23][24][25].…”

Electrical Control of Skyrmion Density via Skyrmion-Stripe Transformation

“…Magnetic skyrmions are topologically stable magnetization states that are particlelike and nanoscale in size [1][2][3][4]. These magnetic skyrmions can be propagated using various techniques, such as spin torques [5][6][7][8][9], spin waves [10][11][12], electric fields [13], and magnetostatic energy gradients [14][15][16][17][18][19]. Hence, magnetic skyrmions are a promising candidate for nanoscale devices with a wide range of applications, such as memory storage [1], computational logic [20][21][22][23], neuromorphic computing [24][25][26][27][28], and probabilistic computing [29,30].…”