3 papers
quant-ph2026
Geometric bounds on multiparameter Heisenberg scaling in optical metrology with limited squeezed resources
Atmadev Rai, Paolo Facchi, Vincenzo Tamma
The simultaneous estimation of multiple parameters is a central task in quantum metrology, distributed sensing, and the calibration of large photonic interferometers. A fundamental…
quant-ph2025
Multiparameter quantum metrology at Heisenberg scaling for an arbitrary two-channel linear interferometer with squeezed light
Atmadev Rai, Danilo Triggiani, Paolo Facchi +1
We present a framework for simultaneously estimating all four real parameters of a general two-channel unitary U(2) with Heisenberg-scaling precision. We derive analytical expressi…
quant-ph2024
Quantum-limited estimation of the frequency shift between two interfering photons by time sampling of their quantum beats
Luca Maggio, Danilo Triggiani, Paolo Facchi +1
We present a sensing scheme for estimating the frequency difference of two non-entangled photons. The technique consists of time-resolving sampling measurements at the output of a…