Composite-pulse enhanced room-temperature diamond magnetometry

The sensitivity of practical solid quantum sensing can be boosted up by increasing the number probes. However, effects spin dephasing caused inhomogeneous broadening and imperfect control reduce fidelity with dense ensemble probes, such as nitrogen-vacancy (NV) centers in diamond. Here, we present a robust effective composite-pulse for high operation against errors via optimized modulation field. Such was verified on NV center to keep spectrum detuning large 110% Rabi frequency. magnetometer experimentally improved factor 4, comparing dynamical decoupling normal rectangular pulse. Our work marks an important step towards trustworthy ultra-sensitive applications. used principle is universal not restricted magnetometer.