Single spin defects in hexagonal boron nitride nanosheets and nanotube

The discovery of spin color centers in hexagonal boron nitride (hBN), a 2D van der Waals (vdW) material, has unlocked exciting opportunities for quantum sensing. With its layered structure, hBN can be easily exfoliated and integrated with various materials and nanostructures, making it ideal for nanoscale sensing applications. Recently, we created single spin defects in hBN nanosheets through carbon-13 ion implantation followed by high-temperature thermal annealing. Using optically detected magnetic resonance (ODMR) spectroscopy, we identified three distinct types of spin defects. We further achieved polarization of single carbon-13 nuclear spins and demonstrated atomic-scale nuclear magnetic resonance (NMR) using these defects. Additionally, we discovered optically active single spin defects in boron nitride nanotubes (BNNTs), a 1D vdW material. We developed a deterministic method to transfer BNNTs onto cantilevers, enabling scanning probe magnetometry with high precision. These advances highlight the potential of hBN and BNNT spin defects for quantum sensing applications.