We are pleased to announce a seminar by Dr. Simone Felicetti from the Institute for Photonics and Nanostructures of CNR, to be held on October Friday 22nd in Aula Conversi at 4 pm.
Title: “Critical parametric quantum sensing”
Quantum critical systems in proximity of phase transitions exhibit a divergent susceptibility, suggesting that an arbitrarily-high precision may be achieved when they are used as probes to estimate a physical parameter. However, such an improvement in sensitivity is counterbalanced by the critical slowing down, which implies an inevitable growth of the protocol duration time . Here, we present sensing protocols based on phase transitions observable in a broad class of quantum optical systems. We show that, in spite of the critical slowing down, critical quantum optical probes can achieve quantum advantage in sensing applications . By going beyond the asymptotic regime of parameters , we show that Heisenberg-limited precision can be achieved with current quantum technologies. Finally, we propose specific applications for quantum magnetometry and for superconducting-qubit readout.
 M. M. Rams, P. Sierant, O. Dutta, P. Horodecki, and J. Zakrzewski, Phys. Rev. X 8, 021022 (2018).
 L. Garbe, M. Bina, A. Keller, M. Paris, and S. Felicetti, Phys. Rev. Lett. 124, 120504 (2020).
 R. Di Candia, F. Minganti, K. V. Petrovnin, G. S. Paraoanu, S.Felicetti, arXiv:2107.04503 (2021).
 P. Krantz, A. Bengtsson, M. Simoen, S. Gustavsson, V. Shumeiko, W. D. Oliver, C. M. Wilson, P. Delsing & J. Bylander, Nat. Comm. 7, 11417 (2016).
Talk’s slides can be downloaded here