Strong coupling (SC) between two resonant plasmon modes can result in the formation of new hybrid modes exhibiting Rabi splitting with strong energy exchange at the nanoscale. However, normal Rabi splitting is often limited to ～50–320meV due to the short lifetime of the plasmon mode. Here, we theoretically demonstrate a record Rabi splitting energy as large as 805 meV arising from the SC between the high-Q plasmonic whispering gallery mode and high-Q cavity plasmon resonance supported by a spherical hyperbolic metamaterial cavity, which consists of a dielectric nanosphere core wrapped in 7 alternating layers of silver/dielectric materials. In addition, the new hybrid modes formed by the SC are shown to exhibit an extralong lifetime of up to 71.9–81.6 fs, with the large electric field intensity enhancement at both the dielectric core and the dielectric layers. More importantly, the spectral ranges of SC can be tuned across an ultrabroad range from the visible to the near-IR by simply changing the dielectric core size. These findings may have potential applications in bright single-photon sources.

通过超声辅助的工艺, 利用氧化还原法制备出多价态纳米MnO_x。通过调节超声时间、KMnO₄浓度、烘干温度、反应溶液pH, 探索MnO_x的最佳合成条件。结果表明: 超声时间20 min, 高锰酸钾浓度0.5 mol/L, 烘干温度80 ℃, 反应溶液pH=7的条件下, 合成的样品MnO_x表现出最佳的催化性能, 对100%的NO去除率可持续15 h。采用X射线衍射分析(XRD)、N₂-吸脱附测试、扫描电镜(SEM)、透射电镜(TEM)等技术考察最优催化剂MnO_x的结构和形貌, 借助X射线光电子能谱(XPS)和傅里叶红外分析(FT-IR)研究最优催化剂MnO_x对NO去除的催化氧化机理以及催化剂的失活机制。结果表明, 三维贯穿的多级孔结构, 花瓣状的形貌和弱晶化的晶体结构有利于气体吸附和传输。多价态Mn和氧空位的存在促进了NO和O₂的吸附和激活, 因此最优样品MnO_x表现出优异的NO的常温催化氧化。