Optimal probes for continuous variable quantum illumination

TL;DR

This paper identifies the optimal continuous variable quantum states for illumination at zero reflectivity, showing coherent and two-mode squeezed-vacuum states are optimal or near optimal, supporting practical quantum sensing.

Contribution

It proves the optimal states for quantum illumination at zero reflectivity and analyzes their performance at non-zero reflectivity, highlighting near optimality.

Findings

Coherent states are optimal at zero reflectivity.

Two-mode squeezed-vacuum states are optimal for two-mode illumination.

These states remain near optimal at non-zero reflectivity.

Abstract

Quantum illumination is the task of determining the presence of an object in a noisy environment. We determine the optimal continuous variable states for quantum illumination in the limit of zero object reflectivity. We prove that the optimal single mode state is a coherent state, while the optimal two mode state is the two-mode squeezed-vacuum state. We find that these probes are not optimal at non-zero reflectivity, but remain near optimal. This demonstrates the viability of the continuous variable platform for an experimentally accessible, near optimal quantum illumination implementation.