東北大学
学際科学フロンティア研究所

Magnonics, a rapidly advancing research field focusing on spin wave quanta or 'magnons,' holds promise for applications in data storage, information processing and communication. Despite being relatively young, it boasts advantages such as lower energy consumption, seamless integration with Complementary Metal-Oxide-Semiconductor (CMOS) structures, and adaptable programmability. Utilizing magnons for information encoding offers benefits like longer coherence times and GHz-scale frequencies, facilitating high-speed operations. Exploring magnon interactions with photons and other excitations presents unique advantages for coherent information transfer. One promising but underexplored aspect in this field involves coupling magnons with phonons which are the vibrations of lattice. This coupling shows potential for reducing energy requirements in switching, enhancing spin-current generation, and accelerating information processing. However, a comprehensive understanding of this interaction is still lacking.

In our study, we'll delve into the interaction between magnons and surface acoustic wave (SAW) phonons in thin-film magnetic systems, aiming to uncover novel coupling phenomena. Achieving the strong coupling regime hinges on overcoming the system's energy loss, influenced by the orientation and type of SAW wave. We'll fine-tune magnetic film properties and circuit design to control coupling.

Additionally, we'll analyze the nature of spin dynamics in the coupled modes, determining whether dynamic effects typically observed in thin film magnetic multilayer stacks manifest during the coupling onset. Specifically, the exploration of GHz spin dynamics and transport, propelled by spin-wave coupling with phonons, represents an uncharted research domain that this project, with the appropriate blend of expertise, will delve into. This research holds promise for advancing quantum computing with magnon qubits and pushing forward magnon and quantum information processing technology.