Entanglement-Enhanced Sensing in a Lossy and Noisy Environment

TL;DR

This paper demonstrates an entanglement-enhanced sensing system that maintains a 20% sensitivity advantage over classical methods even in highly lossy and noisy environments, showing promise for practical quantum sensing applications.

Contribution

The authors experimentally realize an entanglement-based sensor resilient to decoherence, achieving significant sensitivity improvements under realistic loss and noise conditions.

Findings

20% signal-to-noise ratio improvement over classical schemes

Resilience to 14 dB loss and 75 dB noise background

Potential for practical quantum sensing technologies

Abstract

Nonclassical states are essential for optics-based quantum information processing, but their fragility limits their utility for practical scenarios in which loss and noise inevitably degrade, if not destroy, nonclassicality. Exploiting nonclassical states in quantum metrology yields sensitivity advantages over all classical schemes delivering the same energy per measurement interval to the sample being probed. These enhancements, almost without exception, are severely diminished by quantum decoherence. Here, we experimentally demonstrate an entanglement-enhanced sensing system that is resilient to quantum decoherence. We employ entanglement to realize a 20% signal-to-noise ratio improvement over the optimum classical scheme in an entanglement-breaking environment plagued by 14 dB of loss and a noise background 75 dB stronger than the returned probe light. Our result suggests that advantageous quantum-sensing technology could be developed for practical situations.