Optimal squeezing for quantum target detection

TL;DR

This paper demonstrates that an idler-free squeezed-state setup can outperform classical coherent-state systems in quantum target detection, quantum illumination, and reading, by optimizing displacement and squeezing.

Contribution

It proves that Gaussian resources without an idler can surpass semiclassical benchmarks, introducing optimized squeezing and displacement as key factors.

Findings

Idler-free squeezed setups outperform classical benchmarks.

Joint optimization of displacement and squeezing enhances performance.

Quantum illumination and reading benefit from optimized Gaussian probes.

Abstract

It is not clear if the performance of a quantum lidar or radar, without an idler and only using Gaussian resources, could exceed the performance of a semiclassical setup based on coherent states and homodyne detection. Here we prove this is indeed the case by showing that an idler-free squeezed-based setup can beat this semiclassical benchmark. More generally, we show that probes whose displacement and squeezing are jointly optimized can strictly outperform coherent states with the same mean number of input photons for both the problems of quantum illumination and reading.