collaborators

6 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-ph2026

Heisenberg-scaling characterization of a two-channel optical network via two-port homodyne detection

Atmadev Rai, Paolo Facchi, Vincenzo Tamma

We present a fully Gaussian and experimentally feasible scheme for the simultaneous estimation of the four real parameters that characterize a two-channel optical network. The sche…

quant-ph2026

Slow convergence of Trotter decomposition for rotations

Paolo Facchi, Francesco Perrini, Vito Viesti

We study the Trotter approximation for a pair of orbital angular momentum operators, and . In particular, we investigate the scaling behavior of the state-dependent Trot…

quant-ph2025

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…

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-ph2025

Heisenberg-scaling sensitivity in the estimation of two parameters in a Mach-Zehnder interferometer

Atmadev Rai, Danilo Triggiani, Paolo Facchi +1

Achieving the ultimate quantum precision in the estimation of multiple physical parameters simultaneously is a challenge in quantum metrology due to fundamental limitations and exp…