Plasmonic skyrmions with bound states in the continuum

Plasmonic skyrmions are a subject of significant interest due to their potential applications in optics, photonics, and electromagnetic wave technology. These skyrmions are created by the interference of surface plasmon polaritons or spoof localized surface plasmons (SLSP), offering new possibilities for controlling light–matter interactions and structuring light. In this study, we have demonstrated the generation of both electric and magnetic skyrmions simultaneously using a rotational symmetric SLSP spiral meta-structure lattice, operating across a broad range from microwave to terahertz frequencies. By implementing them into a resonance configuration of the quasi-bound state in the continuum through symmetry breaking, we enhance the Q factor and fields, resulting in highly sensitive sensing performance. The SLSP metasurface enables tunable plasmonic skyrmions controlled by the incident polarization. Our findings have potential applications in highly sensitive sensing, filtering, modulation, and communication.