Quantum emitters coupled to plasmonic nanostructures can act as exceptionally bright sources of single photons, operating at room temperature. Plasmonic mode volumes supported by these nanostructures can be several orders of magnitude smaller than the cubic wavelength, which leads to dramatically enhanced light–matter interactions and drastically increased photon production rates. However, when increasing the light localization further, these deeply subwavelength modes may in turn hinder the fast outcoupling of photons into free space. Plasmonic hybrid nanostructures combining a highly confined cavity mode and a larger antenna mode circumvent this issue. We establish the fundamental limits for quantum emission enhancement in such systems and find that the best performance is achieved when the cavity and antenna modes differ significantly in size. We experimentally support this idea by photomodifying a nanopatch antenna deterministically assembled around a nanodiamond known to contain a single nitrogen–vacancy (NV) center. As a result, the cavity mode shrinks, further shortening the NV fluorescence lifetime and increasing the single-photon brightness. Our analytical and numerical simulation results provide intuitive insight into the operation of these emitter–cavity–antenna systems and show that this approach could lead to single-photon sources with emission rates up to hundreds of THz and efficiencies close to unity.

中文翻译：

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通过将等离子体纳米腔耦合到强辐射天线实现超快量子光子学

耦合到等离子体纳米结构的量子发射器可以在室温下充当单个光子的异常明亮的光源。这些纳米结构所支持的等离子模式体积可以比立方波长小几个数量级，这导致光-物质相互作用显着增强，光子产生速率大大提高。然而，当进一步增加光的定位时，这些深亚波长模式反过来可能会阻碍光子快速耦合出自由空间。等离子混合纳米结构结合了高度受限的腔模式和较大的天线模式，可以解决此问题。我们建立了此类系统中量子发射增强的基本限制，并发现当腔模和天线模的大小差异显着时，可获得最佳性能。我们通过实验性地修饰确定围绕纳米金刚石组装的纳米贴片天线来支持这一想法，该纳米金刚石已知包含单个氮空位（NV）中心。结果，腔模缩小，进一步缩短了NV荧光寿命并增加了单光子亮度。我们的分析和数值模拟结果提供了对这些发射器-腔体-天线系统操作的直观了解，并表明该方法可能导致发射速率高达数百THz且效率接近于单位的单光子源。进一步缩短了NV荧光寿命并增加了单光子亮度。我们的分析和数值模拟结果提供了对这些发射器-腔体-天线系统操作的直观了解，并表明该方法可能导致发射速率高达数百THz且效率接近于单位的单光子源。进一步缩短了NV荧光寿命并增加了单光子亮度。我们的分析和数值模拟结果提供了对这些发射器-腔体-天线系统操作的直观了解，并表明该方法可能导致发射速率高达数百THz且效率接近于单位的单光子源。