Atomically Modulating Competing Exchange Interactions in Centrosymmetric Skyrmion Hosts GdRu ₂ X ₂ (X = Si and Ge)

Magnetic skyrmions are topologically protected spin states that hold promise for shaping the future of electronics. Despite impressive progress in skyrmion research, the microscopic mechanisms underlying skyrmion phase transitions at specific temperatures and magnetic fields remain elusive. In this work, we systematically study the isostructural centrosymmetric magnets GdRu 2 X 2 (X = Si and Ge) and the role of X‐ p orbitals in modifying magnetic exchange interactions. Electronic structure and exchange interaction evaluations reveal that the more extended Ge‐4 p versus Si‐3 p orbitals enhance competing exchange interactions in GdRu 2 Ge 2 , thereby manifesting the evolution condition of skyrmions in GdRu 2 X 2 . GdRu 2 Ge 2 single crystals exhibit two high‐entropy regions associated with skyrmion phases at 0.9 T ≤ µ 0 H ≤ 1.2 T and 1.3 T ≤ µ 0 H ≤ 1.7 T, 2 K ≤ T ≤ 30 K—lower field and higher temperature conditions than those in the Si counterpart. Transport measurements reveal the topological Hall effect, validating the topologically nontrivial spin textures and Berry curvature. Our work bridges the gap between skyrmion discovery and material design by demonstrating, for the first time, how atomic‐scale control of exchange interactions enables tunable skyrmion phase transitions, making a significant step toward stabilizing skyrmions at desired temperatures and magnetic fields.