Quantum Materials by Design: Synthesis and Chemistry of Spin Defects in BN Systems

Optically addressable spin defects in solid-state materials are leading candidates for nanoscale quantum sensors and repeaters in quantum optical networks. Despite impressive progress with a few systems, including defects in diamond and silicon carbide, the field is yet to identify the ‘ideal’ quantum defect platform. Low optical efficiency, requirements for low temperature operation and challenging processing of bulk crystalline materials are among the current limitations for scaling quantum technologies based on solid-state defects. Recently, work from our groups has shown that hexagonal boron nitride (hBN) is a two-dimensional (2D) material [1] with visible single-photon emitting, spin-active defects[2][3][4]. hBN defects show high brightness, photon purity, as well as signatures of optically addressable spins with room temperature spin coherence, all desirable properties for optical and spin-based quantum technologies. These developments are exciting because 2D material platforms have the potential for scalable material growth, device fabrication, and deterministic defect formation, which are all critical for scaling a quantum platform. To date, the atomic structure of the visible spin defects in hBN has experimentally been linked to carbon impurities, however the exact atomic structures have.

In this project, we will explore the growth of novel forms of carbon-doped BN materials and characterise these materials for the presence of single-photon emitting quantum point defects. Building on recent advances in nanomaterials synthesis, we will employ chemical vapour deposition (CVD) techniques to grow high-quality hexagonal boron nitride (hBN) with controlled carbon incorporation. This includes the use of dual-source precursors to enable precise doping during growth, as well as post-synthetic treatments to tailor defect configurations. Additionally, we will investigate one, two, and three dimensional heterostructures, which offer a platform for engineering hybrid quantum systems with tunable optical and spin properties. The synthesis will be complemented by, for example, by in situ transmission electron microscopy (TEM) and spectroscopic techniques to monitor defect formation and correlate atomic structure with quantum optical behaviour. Other characterisation techniques to be employed will include, e.g., e.g., X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), four-point probe.

By leveraging these synthesis strategies, we aim to establish a pathway toward deterministic creation of carbon-related spin defects in hBN, thereby advancing the material’s potential as a scalable platform for quantum technologies.

[1] Sci Rep 7, 14297 (2017)
[2] Nature Communications, 13, 681, (2022)
[2] Nature Materials (2024)
[3] Nature Communications, 16, 4927 (2025)