Quantum illumination networks

TL;DR

This paper introduces a quantum illumination network with multiple transmitters and a single receiver, enabling quantum advantages in target detection and parameter estimation under more practical, high-power, and complex scenarios.

Contribution

It proposes a novel quantum illumination network design that overcomes previous limitations, allowing quantum advantage with high power and complex targets, and introduces measurement strategies for multi-parameter estimation.

Findings

Quantum advantage achieved with multiple transmitters at high power

Enhanced parameter estimation with network compared to single transmitter

Six-decibel quantum advantage in hypothesis testing at higher power

Abstract

Quantum illumination is an entanglement-based target detection protocol that provides quantum advantages despite the presence of entanglement-breaking noise. However, the advantage of traditional quantum illumination protocols is limited to impractical scenarios with low transmitted power and simple target configurations. In this work, we propose a quantum illumination network to overcome the limitations, via designing a transmitter array and a single receiver antenna. Thanks to multiple transmitters, quantum advantage is achieved even with a high total transmitted power. Moreover, for single-parameter estimation, the advantage of network over a single transmitter case increases with the number of transmitters before saturation. At the same time, complex target configurations with multiple unknown transmissivity or phase parameters can be resolved. Despite the interference of different returning signals at the single antenna and photon-loss due to multiple-access channel, we provide two types of measurement design, one based on parametric-amplification and one based on the correlation-to-displacement conversion (CtoD) to achieve a quantum advantage in estimating all unknown parameters. We also generalize the parameter estimation scenario to a general hypothesis testing scenario, where the six-decibel quantum illumination advantage is achieved at a much greater total probing power.