Site-Controlled Carbon Implantation for Quantum Emitter Engineering in Hexagonal Boron Nitride

Area of Science:

• Quantum technology
• Materials science
• Nanotechnology

Background:

• Position-controlled quantum defects in 2D hexagonal boron nitride (h-BN) are crucial for quantum technologies.
• Previous studies focused on carbon-doped defect-related single-photon emitters (SPEs) but lacked precise position control.

Purpose of the Study:

• To develop a novel method for fabricating position-controlled carbon-defect SPEs in h-BN.
• To enable the creation of precisely positioned SPE arrays for scalable quantum applications.

Main Methods:

• A two-step fabrication process involving helium ion (He+) focused ion beam (FIB) nanopatterning.
• Post-FIB high-temperature annealing in a methane atmosphere for carbon incorporation, followed by annealing in air to enhance SPE quality.

Main Results:

• Achieved sub-30 nm spatial resolution for defect creation using He+ FIB.
• Fabricated carbon-defect SPEs with high brightness (up to 6.7 × 10^6 counts per second).
• Demonstrated enhanced single-photon purity with g2(0) < 0.2.

Conclusions:

• Established a foundational method for scalable production of precisely positioned SPE arrays in h-BN.
• Paved the way for integrating these SPEs into silicon-based photonic platforms for quantum information processing and sensing.