Antiferromagnetic skyrmion lattice reveals incoherent scattering and coherent flow with quantified interactions

Time-resolved pump–probe X-ray microscopy tracks real-time, sublattice-resolved dynamics of a synthetic antiferromagnetic skyrmion lattice. The study reveals two regimes: a low-current incoherent regime where mobile skyrmions scatter off pinned ones and exhibit 3–20 ns recoil—used to extract a short-range exponential skyrmion–skyrmion repulsion with a*(≈44 nm), b*(≈247 nm)—and a high-current coherent viscous-flow regime with uniform lattice translation, negligible inertia, and suppressed skyrmion Hall effect. The results provide a quantitative framework for AFM skyrmion interactions and demonstrate gigahertz-speed, robust transport for dense spintronic devices.