Edge-free continuous MTJ array enables robust skyrmion creation at scaled dimensions

Abstract

Magnetic skyrmions in synthetic antiferromagnetic (SAF) systems are promising information carriers for next-generation spintronic devices owing to their nanoscale size, high stability, and minimized magnetic stray fields. For high-density stationary integration, the SAF architecture is essential to eliminate dipolar crosstalk between adjacent memory cells. However, as conventional discrete magnetic tunnel junction (MTJ) structures are scaled down to achieve such high densities, strong edge-induced effects emerge, leading to increased voltage thresholds for skyrmion nucleation and reduced nucleation speed. Our micromagnetic studies show that Dzyaloshinskii–Moriya interaction boundary constraints at discontinuous edges create a size-dependent energy peak, significantly impacting skyrmion nucleation in scaled nanodevices. To overcome this limitation, we propose a voltage-controlled continuous MTJ (C-MTJ) device array featuring a shared SAF free-layer design that eliminates magnetic boundaries. By suppressing edge-effect-induced constraints, the C-MTJ architecture enables smooth energy evolution and rapid, deterministic skyrmion creation even at scaled dimensions. These findings establish the C-MTJ array as a scalable and energy-efficient platform for high-density skyrmion-based memory and logic applications.