Maximizing information obtainable by quantum sensors through the quantum Zeno effect

Efficient quantum sensing technologies rely on the precise control of quantum sensors, particularly two-level systems or qubits, to optimize estimation processes. We here exploit the quantum Zeno effect (QZE) as a tool for maximizing information obtainable by quantum sensors, with a specific focus on the level avoided-crossing (LAC) phenomenon in qubit systems. While the estimation of the LAC energy splitting has been extensively studied, we emphasize the crucial role that the QZE can play in estimating the coupling strength. We introduce the concept of information amplification by the QZE for a LAC system under off-resonant conditions. The proposed approach has implications for ac magnetic field sensing and the characterization of complex systems, including many-spin systems requiring the estimation of spin-spin couplings. Overall, our findings contribute to the advancement of quantum sensing by leveraging the QZE for improved control and information extraction.