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

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

Nature Photonics

10.1038/s41566-024-01460-9

https://doi.org/10.1038/s41566-024-01460-9

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

plasmons, Quantum optics

17 June 2024

Cai, H., Rasmita, A., He, R., Zhang, Z., Tan, Q., Chen, D., Wang, N., Mu, Z., Eng, J. J. H., She, Y., Pan, N., Wang, Q., Dong, Z., Wang, X., Wang, J., Miao, Y., Singh, R., Qiu, C.-W., Liu, X., & Gao, W. (2024). Charge-depletion-enhanced WSe2 quantum emitters on gold nanogap arrays with near-unity quantum efficiency. Nature Photonics, 18(8), 842–847. https://doi.org/10.1038/s41566-024-01460-9

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.

Publisher Copyright

This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity (MTC) Individual Research Grant
Grant Reference no. : M21K2c0116

This research / project is supported by the National Research Foundation, Singapore - Quantum Engineering Programme
Grant Reference no. : NRF2021-QEP2-01-P01, NRF2021-QEP2-01-P02, NRF2021-QEP2-03-P01, NRF2021-QEP2-03-P10, NRF2022-QEP2-02-P13, NRF2021-QEP2-03-P09

This research / project is supported by the National Research Foundation, Singapore - Competitive Research Programme
Grant Reference no. : NRF-CRP26-2021-0063

This research / project is supported by the Ministry of Education, Singapore - Singapore Ministry of Education (MOE) Academic Research Fund (AcRF) Tier 3
Grant Reference no. : MOE2016-T3-1-327 006

This is a post-peer-review, pre-copyedit version of an article published in Nature Photonics. The final authenticated version is available online at: http://dx.doi.org/10.1038/s41566-024-01460-9.

https://oar.a-star.edu.sg/communities-collections/articles/21805

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Institute of Materials Research & Engineering