Quantum light generation with ultra-high spatial resolution in 2D semiconductors via ultra-low energy electron irradiation

TL;DR

This paper demonstrates a novel method for creating high-quality single photon emitters in 2D materials using ultra-low energy electron irradiation, achieving ultra-high spatial resolution and tunability, which simplifies defect engineering for quantum technologies.

Contribution

It introduces a simple, low-energy electron irradiation technique for defect creation in 2D materials with high spatial precision, improving upon complex existing methods.

Findings

Achieved defect creation with < 50 nm resolution, extendable to 10 nm.

Produced sharp, low-jitter defect emission peaks.

Demonstrated tunability of defect emission via gate voltage and electron energy.

Abstract

Single photon emitters (SPEs) are building blocks of quantum technologies. Defect engineering of 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, we utilise only ultra-low energy electron beam irradiation (5 keV) to create dilute defect density in hBN-encapsulated monolayer MoS2, 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 MoS2 defect complexes. The sharp peaks have low spectral jitter (< 200 {\mu}eV), and are tuneable with gate-voltage and electron beam energy. Use of low-momentum electron irradiation, ease of processing, and high spatial resolution, will disrupt deterministic creation of high-quality SPEs.