Special PME Quantum Seminar - Xingyu Gao

Quantum sensing with spin defects in van der Waals materials

The recent discovery of spin qubits in hexagonal boron nitride (hBN), a two-dimensional (2D) van der Waals (vdW) material, has opened up exciting possibilities for quantum sensing. Leveraging its layered structure, hBN can be exfoliated and seamlessly integrated with diverse materials and nanostructures for in-situ quantum sensing.  In this talk, I will provide a brief overview of recent advancements in quantum sensing and imaging using spin defects in hBN and discuss our contributions to this emerging field. We have demonstrated high-contrast optically detected magnetic resonance (ODMR) in hBN for both boron vacancy defects and single carbon-related defects. I will present our understanding of the optical, spin and chemical structures of the novel carbon related defects. Additionally, we achieved polarization and coherent control of individual nuclear spins in hBN at room temperature, paving the way for manipulation of nuclear spins in vdW materials for quantum information science and technology applications. Recently, we also discovered optically active single spin defects in boron nitride nanotubes (BNNT), a one-dimensional (1D) vdW material. We have developed a method to deterministically transfer a BNNT onto a cantilever and use it to demonstrate scanning probe magnetometry.