Tip-enhanced quantum-sensing spectroscopy for bright and reconfigurable solid-state single-photon emitters

TL;DR

This paper introduces a tip-enhanced spectroscopy technique that precisely controls and reconfigures solid-state single-photon emitters in hBN, enabling highly-sensitive quantum sensing and deterministic photon source applications at room temperature.

Contribution

It presents a novel method for spatially positioning and enhancing single-photon emitters in hBN using tip-coupled cavities, improving their brightness and reconfigurability for quantum sensing.

Findings

Controlled enhancement of excitation and emission rates.

Reconfigurable single-photon sources with optimized purity.

Successful detection of single-spin defects via ODMR.

Abstract

Atom-like defects in hexagonal boron nitride (hBN) provide room-temperature single-photon emission and coherent spin states, making them attractive for quantum-computing and -sensing applications. However, their random spatial and spectral characteristics hamper deterministic coupling with nano-optical cavities, limiting their use as bright single-photon sources and sensitive quantum sensors. Here, we present tip-enhanced quantum-sensing spectroscopy of single-photon emitters in hBN. Through precise spatial positioning of individual emitters within tip-cavities with different plasmon resonances, we adaptively control the enhancement rates of both excitation and emission, as well as the single-photon purity. In this way, optimal selection of their relative contributions can effectively reconfigure solid-state single-photon sources, with simultaneous nano-spectroscopic space- and time-resolved analyses. Furthermore, we demonstrate tip-enhanced quantum-sensing with single spin defects through optically detected magnetic resonance (ODMR) experiments in tip-coupled hBN nanoflakes. Our approach provides a unique pathway toward highly-sensitive and deterministic quantum-sensing with room-temperature single-photon emitters.