Metastability of photonic spin meron lattices in the presence of perturbed spin- orbit coupling

Photonic skyrmions and merons are topological quasiparticles characterized by nontrivial electromagnetic textures, which have received increasing research attention recently, providing novel degree of freedom to manipulate light-matter interactions and exhibiting excellent potential in deep-subwavelength imaging and nanometrology. Here, the topological stability of photonic spin meron lattices, which indicates the invariance of skyrmion number and robustness of spin texture under a continuous deformation of the field configuration, is demonstrated by inducing a perturbation to break the C4 symmetry in the presence spin-orbit coupling in an optical field. We revealed that amplitude perturbation would result in an amplitude-dependent shift of spin center, while phase perturbation leads to the deformation of domain walls, manifesting the metastability of photonic meron. Such spin topology is verified through the interference of plasmonic vortices with a broken rotational symmetry. The results provide new insights on optical topological quasiparticles, which may pave the way towards applications in topological photonics, optical information storage and transfer.

Automated summary

Photonic skyrmions and merons are topological quasiparticles with nontrivial electromagnetic textures, which have great potential in manipulating light-matter interactions and deep-subwavelength imaging. In this study, the topological stability of photonic spin meron lattices is demonstrated by inducing a perturbation to break the C4 symmetry, revealing the metastability of photonic meron. The spin topology is verified through the interference of plasmonic vortices with a broken rotational symmetry, providing new insights into optical topological quasiparticles.