Quantum sensing of power-law spatial and temporal noise correlations

Noise sensing underlies many physical applications including tests of non-classicality, measurement of thermal temperature, verification of correlated phases of quantum matter, and characterization of criticality. While previous works have shown that quantum resources such as entanglement and squeezing can enhance the sensitivity in estimating deterministic signals, less is known about the entanglement advantage in sensing correlated noise. In this work, we compute the fundamental sensitivity limits of quantum sensors in probing correlated noise. We focus on power-law noise correlations, which naturally arise in condensed matter systems with long-range interactions and/or near criticality. Generalizing the result in [1] to temporally correlated noise, we show that the optimal sensing strategy depends on a competition between the sensor measurement-reset times and characteristic noise time scales. Further, applying the result in [2], we prove entanglement advantages in sensing spatial correlations. We provide a detailed characterization of quantum enhancement depending on features of the correlations. Our work can be implemented using state-of-the-art quantum sensing platforms including solid-state defect qubits, superconducting circuits, and neutral atoms.

[1] Yu-Xin Wang et al., arXiv: 2410.05878.

[2] Anthony Brady et al., arXiv: 2412.17903.