Enhanced quantum illumination of a lossy target: A sequential interaction model

TL;DR

This paper demonstrates that using Gaussian two-mode squeezed states improves quantum illumination detection of lossy targets in realistic noisy environments, outperforming classical protocols.

Contribution

It introduces a sequential interaction model that shows enhanced detection performance of TMSS over classical states in realistic settings.

Findings

TMSS achieves higher SNR than classical protocols for low-reflectivity targets.

TMSS remains robust against thermal noise.

Lower quantum Chernoff bound indicates better distinguishability.

Abstract

The effectiveness of quantum illumination (QI) of a lossy target is investigated in a realistic setting in which the signal sequentially interacts with a noisy environment and the target. The target is considered at a temperature distinct from its surroundings, while both the interactions are modeled as an action of independent beam splitters with different reflectivities. The detection performance is quantified using the signal-to-noise ratio (SNR) and the quantum Chernoff bound (QCB), the latter providing an upper bound on the error probability. The performance of the Gaussian two-mode squeezed state (TMSS) is compared with that of the optimal classical protocol based on coherent states (CS). The proposed model shows that TMSS consistently achieves a higher SNR than CS for a low-reflectivity target and an arbitrary phase change and remains robust against thermal noise. Furthermore, a sufficiently lower QCB is obtained for TMSS than in previously reported results, indicating greater distinguishability between the presence and absence of the target. These findings underscore the role of realistic modeling in improving QI-based detection of lossy targets, with potential relevance to quantum radar and lidar systems.