Current-driven magnetic skyrmion diodes controlled by voltage gates in synthetic antiferromagnets

Abstract

Magnetic skyrmions, as promising candidates in various spintronic devices, have been widely studied owing to their particle-like properties, nanoscale size, and low driving current density. Here, we numerically and theoretically investigate the dynamics of current-driven skyrmion passing through a voltage gate in a synthetic antiferromagnetic racetrack. It is found that the critical current required for skyrmion to pass through the voltage gate positively is much less than that for skyrmion to pass through the gate negatively. Furthermore, we systematically study the linear dependence of the minimum velocity of skyrmion on the driving current density and perpendicular magnetic anisotropy (PMA) gradient, and the calculation results are quite consistent with the simulation results. Finally, we find that the variation of the PMA energy with the position of skyrmion can help us to compare the magnitude of resistance force when the skyrmion passes through different voltage gates. Our results can be beneficial for the design and development of skyrmion diodes.

Reconfigurable skyrmion logic gates with auto-annihilating skyrmion function

“…At the same time, the skyrmion shifts laterally towards the upper boundary of the nanotrack due to the Magnus force (F Magnus ) until the repulsive force (F edge ) from the upper boundary reaches equilibrium with the F , Magnus and then moves to the VCMA region approximately horizontally. As the VCMA region is an energy potential barrier region, when the skyrmion moves into the influence region of the potential barrier, it is affected by the repulsion force (F repulsion ) from the VCMA region [37], and this repulsion increases as the distance between the skyrmion and the VCMA region decreases.…”

Dynamics of Elliptical Magnetic Skyrmion in Defective Racetrack

“…Magnetic skyrmion, a topological magnetic structure characterized by a nanometric size and remarkable stability, has gained significant attention since its first experimental observation in 2009 [1][2][3]. Magnetic skyrmion can be used for various spintronic devices, including spin logic gates [4,5], transistor-like devices [6][7][8], spin diodes [9][10][11], spin-torque nano-oscillators [12][13][14], and racetrack memory devices [15,16]. In particular, racetrack memory devices based on a magnetic skyrmion offer the advantages of high storage density and low energy consumption.…”