Quantum Light Generation with Ultra‐High Spatial Resolution in 2D Semiconductors via Ultra‐Low Energy Electron Irradiation

Abstract Single photon emitters (SPEs) are building blocks of quantum technologies. Defect engineering of two‐dimensional (2D) materials is ideal to fabricate SPEs, wherein spatially deterministic and quality‐preserving fabrication methods are critical for integration into quantum devices and cavities. Existing methods use combination of strain and electron irradiation, or ion irradiation, which make fabrication complex, and limited by surrounding lattice damage. Here, only ultra‐low energy electron beam (e‐beam) irradiation (5 keV) is utilized to create dilute defect density in hBN‐encapsulated monolayer MoS 2 , with ultra‐high spatial resolution (<50 nm, extendable to 10 nm). Cryogenic photoluminescence spectra exhibit sharp defect peaks, following power‐law for finite density of single defects, and characteristic Zeeman splitting for MoS 2 defect complexes. The sharp peaks have low spectral jitter (<200 µeV), and are tunable with gate‐voltage and e‐beam energy. Use of low‐momentum electron irradiation, ease of processing, and high spatial resolution, will disrupt deterministic creation of high‐quality SPEs.