228 / 2024-07-30 01:40:46

Tip-Enhanced Photoluminescence for Enhanced Single-Photon Emission from hBN Defects

point defect,Tip,Plasmonic resonance

The emerging fields of quantum computing and quantum communication have highlighted the critical need for high-quality quantum sources capable of operating under ambient conditions with robust performance and stability, while maintaining high security standards. Hexagonal boron nitride (hBN) point defects have emerged as promising single-photon emitters, known for their high purity and stable single-photon emission at room temperature.

In this study, we present a advanced method to enhance both the purity and intensity of single-photon emission using Tip-Enhanced Photoluminescence Spectroscopy (TEPL). This technique harnesses the plasmonic resonance within a gold (Au) nanocavity to achieve significant improvements in emission characteristics. The TEPL approach offers controlled and localized enhancement of the electromagnetic field, enabling superior interaction with hBN point defects.

Furthermore, we demonstrate a substantial enhancement of photoluminescence (PL) signals through the use of thinly spread hBN nanoflakes. When these nanoflakes are optimally distributed on the substrate, the position of the defects is closer to the surface, significantly reducing the cavity mode volume between the gold tip and the substrate. This configuration results in a higher Purcell enhancement. The reduced mode volume enables more efficient coupling of photonic emission to the plasmonic cavity formed by the tip-substrate interaction, thereby significantly enhancing both emission intensity and purity.

Our approach demonstrates that the integration of TEPL with hBN nanoflakes offers a promising approach for developing stable, high-purity single-photon sources at room temperature, contributing to the advancement of quantum technologies and deepening our understanding of nanoscale light-matter interactions.