Coupling of an atom-like emitter to surface plasmons provides a path toward significant optical nonlinearity, which is essential in quantum information processing and quantum networks. A large coupling strength requires nanometer-scale positioning accuracy of the emitter near the surface of the plasmonic structure, which is challenging. We demonstrate the coupling of single localized defects in a tungsten diselenide (WSe2) monolayer self-aligned to the surface plasmon mode of a silver nanowire. The silver nanowire induces a strain gradient on the monolayer at the overlapping area, leading to the formation of localized defect emission sites that are intrinsically close to the surface plasmon. We measure a coupling efficiency with a lower bound of 39% from the emitter into the plasmonic mode of the silver nanowire. This technique offers a way to achieve efficient coupling between plasmonic structures and localized defects of 2D semiconductors.
@article{arxiv.1706.01532,
title = {Coupling emission from single localized defects in 2D semiconductor to surface plasmon polaritons},
author = {Tao Cai and Subhojit Dutta and Shahriar Aghaeimeibodi and Zhili Yang and Sanghee Nah and John T. Fourkas and Edo Waks},
journal= {arXiv preprint arXiv:1706.01532},
year = {2018}
}