Local Plasmon Phase Delay Effect in Plasmon-Exciton Coupling

Manipulating plasmon-exciton coupling is a pivotal desire for many potential applications. Here, it is found that the plasmonic phase delay can modulate the interference-induced asymmetrical spectrum line shape of the plasmon-exciton coupling system considerably. The phase effect in a hybrid system consisting of monolayer WSe2 and an individual gold nanorod is demonstrated. The phase delay can modulate the relative intensities of the coupling modes but not the splitting energy, effective in both weak and strong coupling regimes. There is an excellent agreement between the numerical calculations and the experimental results. The findings reveal that the local phase delay can act as an effective way to manipulate plasmon-exciton coupling properties at the nanoscale.