Efficient Excitation and Hybrid Integration of Surface Magnon Polaritons with Dopant Ensembles for Fault-Tolerant Quantum Control: Fabrication

We demonstrate efficient excitation of surface magnon polaritons (SMPs) in epitaxial YIG films using a meander-type microstrip transducer and realize the integration of SMP devices with dopant ensembles. The optimized transducer achieves broadband and high-efficiency coupling at cryogenic temperatures, enabling robust non-reciprocal propagation and strong local magnetic field confinement. The hybrid SMP–dopant platform exhibits clear signatures of spin–magnon interaction, validating coherent magnetic coupling within solid-state systems. This architecture enables precise, crosstalk-free spin control without micromagnets or static field gradients, offering enhanced scalability and uniformity. These results highlight the potential of SMP-based architectures for energy-efficient and fault-tolerant quantum control.