发表机构
Columbia University; Max Planck Institute for the Structure and Dynamics of Matter; National Institute for Materials Science（哥伦比亚大学; 马普物质结构与动力学研究所; 国立材料研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究构建二维材料基混合等离激元-磁振子平台，借助s-SNOM观测到等离激元与反铁磁有序的耦合，为相关器件开发奠定基础。
AI 中文摘要
等离激元与磁振子的相互作用是长期探索的现象，对基础物理和自旋电子学应用具有重要意义。三维体系中，能量尺度的巨大失配抑制了该耦合，但具有无间隙色散的二维（2D）等离激元可在宽光谱范围与磁振子重叠。尽管已有大量理论预测，磁振子-等离激元相互作用的实验观测仍难以实现。本研究构建了基于二维材料的首创型混合等离激元-磁振子平台，利用太赫兹辐射的散射型扫描近场光学显微镜（s-SNOM），在石墨烯/NiPS₃界面成像传播的等离激元波包，并追踪其在NiPS₃反铁磁相变过程中的动力学。我们观测到，随反铁磁有序出现，等离激元-极化激元色散发生明显重整化。结合互补的拉曼散射和纳米太赫兹光谱，我们揭示了与多磁振子连续区相关的光谱权重重分布和介电屏蔽变化，这是该现象的潜在机制。这些结果为等离激元与反铁磁有序的耦合提供了可靠证据，为二维材料中混合磁振子-等离激元相互作用的潜在平台奠定了基础，为相干自旋-等离激元器件和可调太赫兹自旋电子学组件开辟了新途径。
英文摘要
The interaction between plasmons and magnons is a long-sought phenomenon with implications for fundamental physics and spintronics applications. In three-dimensional systems, this coupling is suppressed by the large mismatch in energy scales, but two-dimensional (2D) plasmons with gapless dispersion can overlap with magnons over a broad spectral range. Despite numerous theoretical predictions, experimental observation of magnon-plasmon interaction has remained elusive. In this work, we study a first-of-its-kind hybrid plasmon-magnon platform based on 2D materials. By deploying scattering-type scanning near-field optical microscopy (s-SNOM) with terahertz radiation, we image propagating plasmon wavepackets at a graphene/NiPS$_3$ interface and track their dynamics across the antiferromagnetic transition of NiPS$_3$. We observe a clear renormalization of the plasmon-polariton dispersion concurrent with the onset of antiferromagnetic order. With complementary Raman scattering and nano-terahertz spectroscopy, we unveil spectral weight redistribution and dielectric screening changes, potentially associated with the multi-magnon continuum, as the underlying mechanism. These results provide solid evidence of coupling between plasmon and antiferromagnetic order, marking a cornerstone for a potential platform for hybrid magnon-plasmon interactions in 2D materials, opening avenues for coherent spin-plasmon devices and tunable terahertz spintronic components.
Comments12 pages, 5 figures
