Tailoring Zero-Field Magnetic Skyrmions in Chiral Multilayers by a Duet of Interlayer Exchange Couplings

Magnetic skyrmions have emerged as promising elements for encoding information toward biomimetic computing applications due to their pseudoparticle nature and efficient coupling to spin currents. A key hindrance for skyrmionic devices is their instability against elongation at zero magnetic field (ZF). Prevailing materials approaches focused on tailoring skyrmion energetics have found ZF configurations to be highly sensitive, which imposes significant growth constraints and limits their device scalability. This work demonstrates that designer ZF skyrmion configurations can be robustly stabilized within chiral multilayer stacks by exploiting a duet of interlayer exchange couplings (IECs). Microscopic imaging experiments show that varying the two IECs enables the coarse and fine-tuning of ZF skyrmion stability and density. Micromagnetic simulations reveal that the duo-IEC approach is distinguished by its influence on the kinetics of skyrmion nucleation, in addition to the ability to tailor energetics, resulting in a substantially expanded parameter space, and enhanced stability for individual ZF skyrmions. This study underscores the importance of IEC as a means of stabilizing and controlling ZF skyrmions, paving the way to scalable skyrmion-based devices. The stabilization of isolated magnetic skyrmions at zero-magnetic-field (ZF) in chiral multilayers is demonstrated by exploiting interlayer exchange couplings (IECs). Using microscopic imaging and micromagnetic simulations, this work establishes the fine-tuning of ZF skyrmion stability and density via their energetics and kinetics. This study underscores the multifaceted role of IEC in multilayers and paves the way to bespoke skyrmionic devices.image