Tailored energy landscapes for programmable skyrmion logic gate architectures.

Magnetic skyrmions offer an excellent prospect for the next-generation spintronic logic and memory applications due to their topological stability, nanoscale size, and efficient current-driven mobility. This work presents a programmable skyrmion-based logic architecture leveraging skyrmion-skyrmion repulsion and tunnelling through geometrically engineered racetracks. Using micromagnetic simulations, we demonstrate various logic gates (AND, OR, NOT, NAND, NOR, XOR) and a half-adder within a compact structure incorporating artificial nucleation centers, clocking notches, and annihilation zones, eliminating additional gate contacts. By carefully analysing the change in energy and the topological charge, designing and optimising logic gates to realise diverse operations with high reliability and efficiency is possible. Most importantly, our design avoids unnecessary skyrmion annihilation, reducing energy and spatial area. These results outline a scalable, energy-efficient strategy for reconfigurable logic-in-memory systems based on skyrmion dynamics. .