RT Journal Article SR Electronic T1 Quantum plasmonic control of trions in a picocavity with monolayer WS2 JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaau8763 DO 10.1126/sciadv.aau8763 VO 5 IS 10 A1 He, Zhe A1 Han, Zehua A1 Yuan, Jiangtan A1 Sinyukov, Alexander M. A1 Eleuch, Hichem A1 Niu, Chao A1 Zhang, Zhenrong A1 Lou, Jun A1 Hu, Jonathan A1 Voronine, Dmitri V. A1 Scully, Marlan O. YR 2019 UL http://advances.sciencemag.org/content/5/10/eaau8763.abstract AB Monitoring and controlling the neutral and charged excitons (trions) in two-dimensional (2D) materials are essential for the development of high-performance devices. However, nanoscale control is challenging because of diffraction-limited spatial resolution of conventional far-field techniques. Here, we extend the classical tip-enhanced photoluminescence based on tip-substrate nanocavity to quantum regime and demonstrate controlled nano-optical imaging, namely, tip-enhanced quantum plasmonics. In addition to improving the spatial resolution, we use the scanning probe to control the optoelectronic response of monolayer WS2 by varying the neutral/charged exciton ratio via charge tunneling in Au-Ag picocavity. We observe trion “hot spots” generated by varying the picometer-scale probe-sample distance and show the effects of weak and strong coupling, which depend on the spatial location. Our experimental results are in agreement with simulations and open an unprecedented view of a new range of quantum plasmonic phenomena with 2D materials that will help to design new quantum optoelectronic devices.