Demonstration of Entanglement-Enhanced Covert Sensing

TL;DR

This paper demonstrates experimentally that entanglement can enhance covert sensing by improving measurement precision while remaining undetectable, approaching quantum limits for secure information processing.

Contribution

It introduces and experimentally validates a new entanglement-enhanced covert sensing protocol that achieves high precision and security simultaneously.

Findings

Entanglement improves phase estimation accuracy under covertness constraints.

The protocol operates near the fundamental quantum limit.

It maintains high probability of remaining undetected.

Abstract

The laws of quantum physics endow superior performance and security for information processing: quantum sensing harnesses nonclassical resources to enable measurement precision unmatched by classical sensing, whereas quantum cryptography aims to unconditionally protect the secrecy of the processed information. Here, we present the theory and experiment for entanglement-enhanced covert sensing, a paradigm that simultaneously offers high measurement precision and data integrity by concealing the probe signal in an ambient noise background so that the execution of the protocol is undetectable with a high probability. We show that entanglement offers a performance boost in estimating the imparted phase by a probed object, as compared to a classical protocol at the same covertness level. The implemented entanglement-enhanced covert sensing protocol operates close to the fundamental quantum limit by virtue of its near-optimum entanglement source and quantum receiver. Our work is expected to create ample opportunities for quantum information processing at unprecedented security and performance levels.