Gravity enhanced quantum spatial target detection

TL;DR

This paper investigates how Earth's spacetime curvature influences quantum illumination for target detection, demonstrating that gravity can enhance detection performance using entangled light in near-Earth conditions.

Contribution

It introduces a model analyzing quantum illumination in curved spacetime, showing gravity's role in improving detection with entangled states over coherent states.

Findings

Entangled state transmitters outperform coherent states in curved spacetime.

Gravity reduces thermal noise, enhancing detection sensitivity.

Model applicable to microwave quantum illumination and future quantum radar.

Abstract

Quantum illumination can utilize entangled light to detect the low-reflectivity target that is hidden in a bright thermal background. This technique is applied to the detection of an object in the curved spacetime of the Earth, in order to explore how the curvature of spacetime affects quantum illumination. It is found that the spatial quantum illumination with entangled state transmitter outperforms that with coherent-state transmitter in the near-Earth curved spacetime. Moreover, either the quantum illumination system or the coherent-state system is employed, and gravity can enhance the spacetime target detection by reducing the thermal signal at the receiver. Besides, our model in principle can be applied to microwave quantum illumination and thus provides, to some degree, a theoretical foundation for the upcoming spatial quantum radar technologies.