19. Selective decoupling and Hamiltonian engineering in dipolar spin networks

Quantum sensors, such as the nitrogen-vacancy (N-V) color center in diamond, are known for their exquisite sensitivity but their performance over time is subject to degradation by environmental noise. To improve the long-term robustness of a quantum sensor, here we realize an integrated combinatorial spin sensor in the same micrometer-scale footprint, which exploits two different spin sensitivities to distinct physical quantities to stabilize one spin sensor with local information collected in real time via the second sensor. We show that we can use the electronic spins of a large ensemble of N-V centers as sensors of the local magnetic field fluctuations, affecting both spin sensors, in order to stabilize the output signal of interleaved Ramsey sequences performed on the 14N nuclear spin. An envisioned application of such a device is to sense rotation rates with a stability of several days, allowing navigation with limited or no requirement for geolocalization. Our results would enable stable rotation sensing for over several hours, which already reflects better performance than microelectromechanical systems (MEMS) gyroscopes of comparable sensitivity and size.