Controlling the interaction between the excitonic states of a quantum emitter and the plasmonic modes of a nanocavity is key for the development of quantum information processing devices. In this Letter we demonstrate that the tunnel electroluminescence of electrically insulated C₆₀ nanocrystals enclosed in the plasmonic nanocavity at the junction of a scanning tunneling microscope can be switched from a broad emission spectrum, revealing the plasmonic modes of the cavity, to a narrow band emission, displaying only the excitonic states of the C₆₀ molecules by changing the bias voltage applied to the junction. Interestingly, excitonic emission dominates the spectra in the high-voltage region in which the simultaneously acquired inelastic rate is low, demonstrating that the excitons cannot be created by an inelastic tunnel process. These results point toward new possible mechanisms for tunnel electroluminescence of quantum emitters and offer new avenues to develop electrically tunable nanoscale light sources.

中文翻译：

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选择性地解决托管量子发射器的纳米腔中的等离子体模式和激子状态

控制量子发射器的激子态与纳米腔的等离子体模式之间的相互作用是开发量子信息处理设备的关键。在这封信中，我们证明了封闭在扫描隧道显微镜连接处的等离子体纳米腔中的电绝缘 C ₆₀纳米晶体的隧道电致发光可以从宽发射光谱切换到窄带发射，揭示腔的等离子体模式, 仅显示 C ₆₀的激子态通过改变施加到结的偏压来改变分子。有趣的是，激子发射在同时获得的非弹性率较低的高压区域主导光谱，表明激子不能由非弹性隧道过程产生。这些结果指向了量子发射器隧道电致发光的新可能机制，并为开发电可调纳米级光源提供了新途径。