A detailed description of the experimental realisation of quantum illumination protocol

TL;DR

This paper reports the first detailed experimental realization of quantum illumination, demonstrating its robustness in noisy environments and its potential for practical quantum sensing applications.

Contribution

It presents the first detailed experimental implementation of quantum illumination using photon number correlations, showing robustness against noise and losses.

Findings

Quantum illumination outperforms classical methods in noisy environments.

Photon number correlations enable effective quantum detection.

The experiment demonstrates practical feasibility of quantum sensing in real-world conditions.

Abstract

In the last years the exploitation of specific properties of quantum states has disclosed the possibility of realising tasks beyond classical limits, creating the new field of quantum technologies [1, 2, 3, 4, 5, 6, 7, 8, 9]. Among them, quantum metrology and imaging aim to improve the sensitivity and/or resolution of measurements exploiting non-classical features such as squeezing and quantum correlations (entanglement and discordant states) [10, 11, 12, 13, 14]. Nevertheless, in most of the realistic scenarios losses and noise are known to nullify the advantage of adopting quantum strategies [15]. In this paper we describe in detail the first experimental realization of quantum illumination protocol aimed to target detection in a noisy environment, that preserves a strong advantage over the classical counterparts even in presence of large amount of noise and losses. The experiment, inspired by the theoretical ideas elaborated in [16, 17, 18, 19] (see also [20, 21]), has been performed exploiting only photon number correlations in twin beams. Thus, for its simplicity it can find widespread use. Even more important by challenging the common believe that real application of quantum technologies is limited by their fragility to noise and losses, it paves the way to their real application.