Researchers Yuhang Ren and Susumu Takahashi from UCLA have successfully identified and characterized a single nitrogen vacancy (NV) center coupled to two electron spins, providing valuable insights for quantum sensing and quantum simulation. Using NV-detected electron paramagnetic resonance (EPR) spectroscopy, they precisely determined the number of detected spins and their interaction strengths. Their findings suggest that the detected spins originate from diamond surface spins, highlighting the potential of this method for studying interacting spin systems and enabling entangled sensing.

This breakthrough was made possible using nanostructured diamond with out-of-plane (111)-oriented NV centers, specially fabricated by the Qnami Foundry. The unique nanopillar architecture enhances spin detection sensitivity, demonstrating the power of engineered diamond for next-generation quantum experiments.