Optical quantum emitters in monolayer MoS₂ fabricated with nm-precision by He ion microscopy

Atomistic defects in semiconductors can serve as single photon emitters for applications in quantum technologies. However, in conventional semiconductors, defects are often buried in the bulk hampering integration of defect centers into photonic circuits. Recently, it was demonstrated that color centers with narrow emsission are generated in single layer MoS₂ by focused He-ion beam irradiation [1], opening a natural pathway for device integration.
Here, we investigate atomistic defects in MoS₂ deliberately induced by focused He ion bombardment. We use scanning tunneling microscopy (STM) to resolve the atomistic defect states. By imaging line patterns with atomic resolution, we can quantify the lateral resolution of the defect patterning to be better than 7 nm.

[1] Klein et al. Site-selectively generated photon emitters in monolayer MoS2 via local helium ion irradiation, Nature Communications 10, 2755 (2019).