Topological stability and transitions of photonic meron lattices at the metal/uniaxial crystal interface

Optical topological quasiparticles with nontrivial topological textures, such as skyrmions and meron lattices, have attracted considerable attention due to their potential applications in high-dimensional optical data storage and communications. Most previous studies of optical topological quasiparticles have focused on the formation of topological structures in isotropic media, whereas in our work, we perform a comprehensive investigation into the formation, topological stability, and phase transitions of optical meron lattices at the metal/uniaxial crystal interface. Our theoretical studies show that by rotating the optical axis orientation of the uniaxial crystal, meron lattices constructed by electric-field vector undergo phase transitions from a topologically nontrivial to a topologically trivial state, whereas the skyrmion number of the spin meron lattices remains robust against such rotations. The findings offer new insights into the topological stability and phase transitions of topological quasiparticles under light–matter interactions and hold promise for applications in optical data storage, information encryption, and communications.