Single nuclear spin detection and control in a van der Waals material.

Optically active spin defects in solids are leading candidates for quantum sensing and quantum networking. Recently, single spin defects were discovered in hexagonal boron nitride (hBN), a layered van der Waals (vdW) material. Owing to its two-dimensional structure, hBN allows spin defects to be positioned closer to target samples than in three-dimensional crystals, making it ideal for atomic-scale quantum sensing, including nuclear magnetic resonance (NMR) of single molecules.

A Power-Efficient Coplanar Waveguide Design for Enhanced Optical Readout in h-BN Quantum Sensors.

The past decade has witnessed a growing research interest in quantum sensing using spin-active boron vacancy () defects in hexagonal boron nitride (hBN). While hBN enables easy chip integration, current quantum sensing devices suffer from low optical readout and noisy signals due to inefficient waveguide designs that limit microwave absorption, resulting in reduced optically detected magnetic resonance (ODMR) contrast. This study advances hBN-integrated quantum sensors through three generations, culminating in a compact single-port coplanar waveguide (CPW).

Nanotube spin defects for omnidirectional magnetic field sensing.

Optically addressable spin defects in three-dimensional (3D) crystals and two-dimensional (2D) van der Waals (vdW) materials are revolutionizing nanoscale quantum sensing. Spin defects in one-dimensional (1D) vdW nanotubes will provide unique opportunities due to their small sizes in two dimensions and absence of dangling bonds on side walls. However, optically detected magnetic resonance of localized spin defects in a nanotube has not been observed.