Quantum Magnonics: A Versatile Interface for Interconnected Quantum Systems

Speaker: Seminar by Prof. Marius Costache, Universitat de Barcelona, Spain. 

Title: Quantum Magnonics: A Versatile Interface for Interconnected Quantum Systems

Abstract: The rapid advancement of quantum technologies has led to the development of diverse platforms including superconducting qubits, photons, and mechanical resonators. While these systems excel at specific tasks such as processing, transmitting, or storing information, a significant bottleneck remains in the lack of seamless communication between these fundamentally different modalities. Building scalable quantum networks and architectures requires reliable quantum transducers capable of converting information between incompatible systems without decohering fragile quantum states.

This seminar explores the emerging field of quantum magnonics, where collective magnetic excitations, or magnons, serve as a versatile bridge. Due to their high tunability and ability to couple strongly across microwave, optical, and mechanical domains, magnons offer a promising foundation for the interconnected, multi-modal quantum systems of the future. In particular, I will discuss two experiments that highlight this potential. First, we demonstrate strong, coherent coupling between microwave photons and magnons in the van der Waals magnet Cr2Ge2Te6, achieving coupling strengths up to 1 GHz and establishing these 2D Heisenberg systems as a robust platform for cavity-mediated quantum control. Second, we present the design of an opto-magnon-mechanical crystal that leverages a mechanical mediator to achieve enhanced photon-magnon interaction, overcoming the coupling limitations of traditional direct-coupling systems. By integrating a high-quality optical cavity with high magnon-mechanical and optomechanical coupling strengths, this architecture provides a highly tunable platform for the precise measurement and control of novel quantum states of matter.

All interested are welcome!