Temporal topological state transitions of optical skyrmion lattices

We demonstrate temporal topological phase transitions in optical skyrmion lattices through the superposition of orthogonally polarized plane waves with different frequencies. By introducing a frequency offset between left- and right-circularly polarized components, we enable dynamic modulation of skyrmion configurations while preserving the lattice's spatial periodicity. This approach facilitates a continuous and periodic evolution between Bloch-type and Néel-type configurations within an individual unit cell, governed by time-dependent phase evolution. The universality of this approach is demonstrated across multiple lattice symmetries, where the Stokes vectors evolve continuously while the topological skyrmion numbers remain unchanged, thereby confirming the existence of topological protection. This temporal degree of freedom extends the control of skyrmion beyond spatial constraints, providing new opportunities for studying complex light-matter interactions and topological information processing.