Electrical manipulation of the fine-structure splitting of WSe2 quantum emitters

We report on the modulation of the fine-structure splitting of quantum-confined excitons in localized quantum emitters hosted by a monolayer transition metal dichalcogenide (TMDC). The monolayer TMDC, tungsten diselenide (WSe2), is encapsulated in a van der Waals heterostructure which enables the application of an external electric field on the quantum-dot-like emitters hosted by the monolayer flake. The emitters exhibit quantum-confined Stark effect and a modulation in the fine-structure splitting (FSS) as a function of electric field. A maximum modulation of 1500 mu eV is observed in the FSS from the studied emitters. Finally, we measure the polarization response of the localized exciton emission as a function of electric field exhibiting strong circular polarization with decreasing fine-structure splitting, further confirming the suppression of the anisotropic electron-hole exchange interaction thats causes the FSS.