Strong on-Chip Microwave Photon–Magnon Coupling Using Ultralow-Damping Epitaxial Y<sub>3</sub>Fe<sub>5</sub>O<sub>12</sub> Films at 2 K
Side Guo, Daniel Russell, Joseph Lanier, Haotian Da, P. C. Hammel, Fengyuan Yang
Abstract
Y 3 Fe 5 O 12 is arguably the best magnetic material for magnonic quantum information science (QIS) because of its extremely low damping. We report ultralow damping at 2 K in epitaxial Y 3 Fe 5 O 12 thin films grown on a diamagnetic Y 3 Sc 2 Ga 3 O 12 substrate that contains no rare-earth elements. Using these ultralow damping YIG films, we demonstrate for the first time strong coupling between magnons in patterned YIG thin films and microwave photons in a superconducting Nb resonator. This result paves the road toward scalable hybrid quantum systems that integrate superconducting microwave resonators, YIG film magnon conduits, and superconducting qubits into on-chip QIS devices.