Quantum plasmonic control of trions in a picocavity with monolayer WS2

Zhe He, Zehua Han, Jiangtan Yuan, Alexander M. Sinyukov, Hichem Eleuch, Chao Niu, Zhenrong Zhang, Jun Lou, Jonathan Hu, Dmitri V. Voronine, Marlan O. Scully
2019 Science Advances  
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.
more » ... uantum 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.
doi:10.1126/sciadv.aau8763 fatcat:xzhcd4j5yfcszgmjteoguulpie