State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, Department of Physics, Peking University, Beijing, 100871, China.
Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0021, Japan.
Nat Commun. 2018 Nov 19;9(1):4858. doi: 10.1038/s41467-018-07356-x.
Strong coupling between two resonance modes leads to the formation of new hybrid modes exhibiting disparate characteristics owing to the reversible exchange of information between different uncoupled modes. Here, we realize the strong coupling between the localized surface plasmon resonance and surface plasmon polariton Bloch wave using multilayer nanostructures. An anticrossing behavior with a splitting energy of 144 meV can be observed from the far-field spectra. More importantly, we investigate the near-field properties in both the frequency and time domains using photoemission electron microscopy. In the frequency domain, the near-field spectra visually demonstrate normal-mode splitting and display the extent of coupling. Importantly, the variation of the dephasing time of the hybrid modes against the detuning is observed directly in the time domain. These findings signify the evolution of the dissipation and the exchange of information in plasmonic strong coupling systems and pave the way to manipulate the dephasing time of plasmon modes, which can benefit many applications of plasmonics.
两种共振模式的强耦合导致新的混合模式的形成，由于不同非耦合模式之间信息的可逆交换，这些混合模式表现出不同的特性。在这里，我们使用多层纳米结构实现了局域表面等离激元共振和表面等离激元布洛赫波之间的强耦合。从远场光谱中可以观察到具有 144 meV 分裂能的交叉行为。更重要的是，我们使用光发射电子显微镜在频域和时域中研究了近场特性。在频域中，近场光谱直观地演示了模式分裂，并显示了耦合的程度。重要的是，在时域中可以直接观察到混合模式的退相时间随失谐的变化。这些发现标志着等离子体强耦合系统中耗散和信息交换的演变，并为控制等离子体模式的退相时间铺平了道路，这将有益于等离子体学的许多应用。
