论文标题
巨大的MID-IR谐振耦合与等离子多层元的亚NM间隙中的分子振动
Giant mid-IR resonant coupling to molecular vibrations in sub-nm gaps of plasmonic multilayer metafilms
论文作者
论文摘要
能够限制光的纳米材料对于增强光谱镜，例如拉曼散射，红外吸收和非线性光学过程是可取的。等离子超级晶格已经显示出在中红外托管集体共振的能力，但需要严格的制造工艺才能创建有序的结构。在这里，我们证明了镜子上的短距离Au纳米颗粒多层的多层，由亚NM分子间隔者自我组装，支持可见和红外线中的集体等离子体 - 核酸杆菌共振，连续可调，超过11 $ $ m，仅通过nanoparticle尺寸和数字来衡量nanoparticle尺寸和数字。由此产生的分子 - 平板系统方法方法振动强耦合，并显示巨大的Fano浸入强度，Seira增强因子〜10 $^6 $，轻度耦合强度G〜100 cm $^{ - 1} $，PURCELL因子〜10 $^6 $，以及模式压缩因子〜10 $^8 $^8 $^8 $。集体等离子 - 孔子模式对纳米颗粒空位障碍非常健壮，并且由分子间隔者定义的一致的间隙尺寸维持。结构性障碍有效地将光线融合到多层和镜子之间的间隙中，从而使拉曼和红外样品的样品体积感测。
Nanomaterials capable of confining light are desirable for enhancing spectroscopies such as Raman scattering, infrared absorption, and nonlinear optical processes. Plasmonic superlattices have shown the ability to host collective resonances in the mid-infrared, but require stringent fabrication processes to create well-ordered structures. Here, we demonstrate how short-range-ordered Au nanoparticle multilayers on a mirror, self-assembled by a sub-nm molecular spacer, support collective plasmon-polariton resonances in the visible and infrared, continuously tunable beyond 11 $μ$m by simply varying the nanoparticle size and number of layers. The resulting molecule-plasmon system approaches vibrational strong coupling, and displays giant Fano dip strengths, SEIRA enhancement factors ~10$^6$, light-matter coupling strengths g~100 cm$^{-1}$, Purcell factors ~10$^6$, and mode volume compression factors ~10$^8$. The collective plasmon-polariton mode is highly robust to nanoparticle vacancy disorder and is sustained by the consistent gap size defined by the molecular spacer. Structural disorder efficiently couples light into the gaps between the multilayers and mirror, enabling Raman and infrared sensing of sub-picolitre sample volumes.
