袁怀洋在IUMRS-ICEM国际会议上做邀请报告
Conference: 18th International Conference on Electronic Materials 2024 (IUMRS-ICEM 2024), Hong Kong, 17 to 20 May 2024
Title: Breaking surface plasmon excitation constraint via surface spin waves
Abstract:
Understanding the light-matter interaction is a central topic in condensed matter physics. Light can induce electron oscillation on the metallic surface and in 2D conducting materials, so-called surface plasmons, which is promising if one wants to confine and amplify electromagnetic waves for sensing applications. Therefore, surface plasmons in two-dimensional electron systems have attracted great attention in the last few decades. However, the excitation of a surface plasmon, in particular, transverse-electric (TE) surface plasmon, remains an outstanding challenge due to the difficulty in conserving energy and momentum simultaneously in normal 2D materials. In this talk, we show that the TE surface plasmons ranging from gigahertz to terahertz regime can be effectively excited and manipulated in a hybrid dielectric, 2D material and magnet structure. The essential physics is that the surface spin wave supplements an additional freedom of surface plasmon excitation and thus greatly enhances the electric field in the 2D medium. Based on widely-used magnetic materials like yttrium iron garnet (YIG) and manganese difluoride (MnF2), we further show that the plasmon excitation manifests itself as a measurable dip in the reflection spectrum of the hybrid system while the dip position and the dip depth can be well controlled by the electric gating on the 2D layer and an external magnetic field [1]. Our findings should bridge the fields of low-dimensional physics, plasmonics, and spintronics and further open a novel route to design plasmonic and spintronic devices in both classical and quantum regimes [2].
Reference:
[1] H. Y. Yuan and Yaroslav Blanter, Breaking surface plasmon excitation constraint via surface spin waves, arXiv:2402.04626v1.
[2] H. Y. Yuan, Y. Cao, A. Kamra, R. A. Duine, and P. Yan, Quantum magnonics: when magnon spintronics meets quantum information science, Phys. Rep. 965, 1 (2022).
