Voltage-driven flexible skyrmioniums for high-speed transport and reversible logic in discrete electrode nanowires.

A magnetic skyrmionium, a composite spin texture formed by merging two topologically distinct skyrmions, is a promising information carrier for high-speed and high-density spintronic devices. Although spin current is a common driving force for skyrmionium dynamics, it can induce Joule heating and compromise device stability. To address this limitation, we investigated a voltage-driven approach for propelling skyrmioniums using discrete electrodes. By eliminating Joule heating, our method enables a maximum skyrmionium speed of 101 m s. We further established a theoretical framework for a flexible skyrmionium, incorporating its deformation into the Thiele equation to more accurately capture the system's dynamics. Leveraging the precise control offered by voltage gates and the pinning effect, we also designed three skyrmionium-based logic gates-including Boolean, INV/COPY and Fredkin gates-to showcase the practical potential of skyrmioniums in logic operations. Our findings not only open a novel pathway for developing advanced spintronic devices but also underscore the reliability of voltage-driven skyrmioniums as a new perspective for studying skyrmionium dynamics.