Work

Heisenberg-Scaling Characterization of a Two-Channel Optical Network via Two-Port Homodyne Detection

Year: 2026

Type: article

Abstract: 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 scheme utilizes a two-mode squeezed probe and balanced homodyne detection at both output ports, for which we derive the complete classical Fisher information matrix analytically. Our scheme achieves the Heisenberg-scaling sensitivity for all four parameters simultaneously, enabling full multiparameter characterization of the two-channel interferometric network. We further show, by maximum-likelihood estimation, that the corresponding multiparameter Cramér-Rao bounds are saturated with a modest number of experimental repetitions and for low photon number. The scheme establishes a practical route to Heisenberg-scaling multiparameter Gaussian metrology for a two-channel network, with direct relevance to calibration and sensing in integrated photonics and distributed quantum-enhanced measurement architectures.

Source: Physical Review Letters

DOI: 10.1103/y9wq-hhg2

Authors: Atmadev Rai, Paolo Facchi, Vincenzo Tamma

Institutions: University of Portsmouth, Istituto Nazionale di Fisica Nucleare, Sezione di Bari, University of Bari Aldo Moro, Polytechnic University of Bari

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green