Nuclear spin assisted magnetic field angle sensing

Abstract Quantum sensing exploits the strong sensitivity of quantum systems to measure small external signals. The nitrogen-vacancy (NV) center in diamond is one most promising platforms for real-world applications, predominantly used as a magnetometer. However, its magnetic field vanishes when bias acts perpendicular NV axis. Here, we introduce different strategy assisted by nitrogen nuclear spin that uses entanglement between electron and spins restore sensitivity. This, turn, allows us detect changes angle relative Furthermore, based on same underlying principle, show coupling strength noise, hence coherence time, exhibits asymmetric dependence. This uncover directional properties local environment realize maximal decoupling from anisotropic noise.