Model-free Error Mitigation in NV-Center Magnetometry

Quantum sensing is an emerging field with the potential to outperform classical methods in both precision and spatial resolution.

The sensitivity of the underlying quantum platform however also makes them highly susceptible to their environmental noise. To address this issue, techniques from the field of quantum error mitigation have been used to improve measurement results from noisy device signals via post-processing.

Here we present a novel mitigation technique for quantum sensors to efficiently reverse the effects of any noise source that can be described by a completely positive trace preserving (CPTP) map.

The method neither requires tomography of the final density matrix after the sensing protocol nor an underlying noise-model. It leverages the knowledge acquired by a pre-characterization step of the device to automatically adapt to the complexity of the dissipative evolution and to indicate which sensing times are best suited for the most accurate results. This method represents a further step toward perfecting a new family of sensors with the smallest scale of resolution, enabling measurements at the molecular scale.