Luiz Davidovich

Quantum sensors enable parameter estimation with greater precision than classical methods. Devices based on quantum physics have enabled accurate measurements of the gravitational field, detailed brain imaging, detection of gravitational-wave sources over 400 million light-years away, and increasingly precise time measurements.
Quantum metrology is the conceptual framework that encompasses these devices. This talk reviews recent advances in this field, including precision limits for noisy systems [1,2,3], with applications to estimating absorption [4,5] and the depolarization of light [6]. In particular, the role of entanglement in open-system metrology is discussed, and it is shown that quantum advantage in metrological tasks may persist and even increase after initial entanglement is lost due to noise.

[1] B. M. Escher, R. L. de Matos Filho, and L. Davidovich, Nature Physics 7, 406 (2011)
[2] B. M. Escher, R. L. de Matos Filho, and L. Davidovich, Braz. J. Phys. 41, 229 (2011)
[3] C. L. Latune, B. M. Escher, R. L. de Matos Filho, and L. Davidovich, Phys. Rev. A 88, 042112 (2013)
[4] J. Wang, L. Davidovich, and G. S. Agarwal, Physical Review Research 2, 033389 (2020)
[5] J. Wang, R. L. de Matos Filho, G. S. Agarwal, and L. Davidovich, Physical Review Research 6, 013034 (2024)
[6] L. Davidovich and R. L. de Matos Filho, Physical Review A 108, 042612 (2023)