Harnessing Light to Generate and Probe Magnons in Two-Dimensional Magnets

量子物理学・ナノサイエンス第456回セミナー

概要

Two-dimensional magnetic materials provide a versatile platform for controlling collective spin excitations and exploring their topological and quantum-geometric properties. Of particular interest is the generation and manipulation of magnon spin currents, which could enable low-dissipation information transport, while topological magnons offer the prospect of robust, directional spin transport protected against imperfections. Beyond topology, the quantum geometry of magnon bands contains information about the magnon wavefunctions that is inaccessible from the excitation spectrum alone, providing a new avenue for characterizing magnetic materials. In this talk, I will discuss how light can be used both to control and to probe these phenomena. I will present mechanisms for the all-optical generation of magnon spin currents [1], as well as optical approaches to access the topology and quantum geometry of magnon bands [2, 3]. Combined with an optical cavity, these mechanisms can be leveraged to generate steady states of squeezed magnon pairs [4]. Finally, I will discuss how THz spectroscopy and cavity coupling can reveal signatures of topological magnon edge states [5]. Together, these theoretical results demonstrate how light–magnon interactions provide powerful tools to generate, probe, and characterize magnon transport and collective excitations in two-dimensional magnetic materials.

　　　　 　　　　
• [1] E. Viñas Boström, T. S. Parvini, J. W. McIver, A. Rubio, S. Viola Kusminskiy, M. A. Sentef; Phys. Rev. B 104, L100404 (2021)
• [2] E. Viñas Boström, T. S. Parvini, J. W. McIver, A. Rubio, S. Viola Kusminskiy, M. A. Sentef; Phys. Rev. Lett. 130, 026701 (2023)
• [3] E. Viñas Boström, T. S. Parvini, J. W. McIver, A. Rubio, S. Viola Kusminskiy, M. A. Sentef; Phys. Rev. Lett. 130, 026701 (2023)
• [4] T. S. Parvini, A.-L. E. Römling, S. Sharma, S. Viola Kusminskiy; Phys. Rev. B 111, 014416 (2025)
• [5] I. Mohanty, J. Knolle, S. Viola Kusminskiy; arXiv:2607.23170 (2026)
　　　　

• 量子物理学・ナノサイエンス第456回セミナー

• 東京科学大学理学院・物理学系 ナノサイエンスを拓く量子物理学拠点　共催