Achieving unity quantum efficiency in single-photon emitters (SPEs) is a holy grail in quantum information science. Through plasmonic coupling it is possible to increase the quantum efficiency of SPEs by increasing the radiative decay rate, but to approach unity quantum efficiency, non-radiative decay must be mitigated. Here we show that non-radiative decay in two-dimensional WSe₂ quantum emitters can be electrically suppressed through charge depletion by using dual gate configurations under a large electric field. In this condition, for site-controlled SPEs in WSe₂ coupled to gold nanogaps, the SPE transition quantum efficiency after gating is increased to 76.4 ± 14.6% on average, with some SPEs reaching near-unity (more than 90%) quantum efficiency. This study provides a new approach for tuning SPEs with an applied gate voltage and motivates further theoretical and experimental studies of SPE enhancement on vertically aligned nanogaps.

在单光子发射器（SPE）中实现单位量子效率是量子信息科学的一个圣杯。通过等离子体耦合，可以通过增加辐射衰变率来提高 SPE 的量子效率，但为了接近统一量子效率，必须减轻非辐射衰变。在这里，我们表明，通过在大电场下使用双栅极配置，可以通过电荷耗尽来电抑制二维 WSe ₂量子发射器中的非辐射衰变。在此条件下，对于与金纳米间隙耦合的WSe ₂中的位点控制SPE，门控后的SPE跃迁量子效率平均提高至76.4±14.6％，其中一些SPE达到接近一致（超过90％）的量子效率。这项研究提供了一种通过施加栅极电压来调节 SPE 的新方法，并激发了对垂直排列纳米间隙上 SPE 增强的进一步理论和实验研究。