近日，新加坡南洋理工大学的Weibo Gao及其研究团队取得一项新进展。经过不懈努力，他们实现具有接近1量子效率的金纳米间隙阵列上的电荷耗尽增强WSe₂量子发射器。相关研究成果已于2024年6月17日在国际知名学术期刊《自然—光子学》上发表。

该研究团队证明了二维WSe₂量子发射器中的非辐射衰变，可以通过在大电场下使用双门结构的电荷耗尽来进行电抑制。在此条件下，与金纳米间隙耦合的WSe₂中格位受控SPE，门控后的SPE跃迁量子效率平均提高到76.4±14.6%，部分SPE达到接近1的量子效率(90%以上)。该研究为外加门电压调谐SPE提供了新的方法，并激发了垂直排列纳米间隙上SPE增强的进一步理论和实验研究。

据悉，实现单光子发射器(SPEs)的单位量子效率是量子信息科学的圣杯。通过等离子体耦合，可以通过提高辐射衰变速率来提高SPEs的量子效率，但要达到单位量子效率，必须减轻非辐射衰变。

附：英文原文

Title: Charge-depletion-enhanced WSe₂ quantum emitters on gold nanogap arrays with near-unity quantum efficiency

Author: Cai, Hongbing, Rasmita, Abdullah, He, Ruihua, Zhang, Zhaowei, Tan, Qinghai, Chen, Disheng, Wang, Naizhou, Mu, Zhao, Eng, John J. H., She, Yongzhi, Pan, Nan, Wang, Qian, Dong, Zhaogang, Wang, Xiaoping, Wang, Juan, Miao, Yansong, Singh, Ranjan, Qiu, Cheng-Wei, Liu, Xiaogang, Gao, Weibo

Issue&Volume: 2024-06-17

Abstract: 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.

DOI: 10.1038/s41566-024-01460-9

Source: https://www.nature.com/articles/s41566-024-01460-9