Demonstration of a Reconfigurable Entangled Radio-Frequency Photonic Sensor Network

TLDR

Quantum metrology uses entanglement to surpass the standard quantum limit, yet demonstrations have largely focused on single sensors while many applications demand coordinated multi‑sensor networks. We propose and experimentally demonstrate a reconfigurable sensor network based on continuous‑variable multipartite entanglement. The network comprises three nodes with electro‑optic transducers, and by tailoring the multipartite entangled states it can be reconfigured to maximize quantum advantage for distributed RF sensing tasks such as angle‑of‑arrival estimation. Our results link entanglement structure to quantum advantage in distributed sensing and reveal rich physics that could enable ultrasensitive positioning, navigation, and timing.

Abstract

Quantum metrology takes advantage of nonclassical resources such as entanglement to achieve a sensitivity level below the standard quantum limit. To date, almost all quantum-metrology demonstrations are restricted to improving the measurement performance at a single sensor, but a plethora of applications require multiple sensors that work jointly to tackle distributed sensing problems. Here, we propose and experimentally demonstrate a reconfigurable sensor network empowered by continuous-variable (CV) multipartite entanglement. Our experiment establishes a connection between the entanglement structure and the achievable quantum advantage in different distributed sensing problems. The demonstrated entangled sensor network is composed of three sensor nodes each equipped with an electro-optic transducer for the detection of radio-frequency (RF) signals. By properly tailoring the CV multipartite entangled states, the entangled sensor network can be reconfigured to maximize the quantum advantage in distributed RF sensing problems such as measuring the angle of arrival of an RF field. The rich physics of CV multipartite entanglement unveiled by our work would open a new avenue for distributed quantum sensing and would lead to applications in ultrasensitive positioning, navigation, and timing.