Quantum-enhanced interferometry by entanglement-assisted rejection of environmental noise

TL;DR

This paper demonstrates that entangled quantum states can significantly improve phase estimation precision in noisy, lossy interferometers, especially when accounting for environmental phase fluctuations, advancing quantum sensing in challenging conditions.

Contribution

It introduces a theoretical comparison of three illumination strategies, highlighting the advantage of entangled probes in noisy environments with phase fluctuations.

Findings

Entangled probes outperform classical strategies in noisy, lossy interferometers.

The advantage scales with the number of entangled modes.

The work provides a theoretical basis for using multimode entangled states in practical quantum sensing.

Abstract

Sensing and measurement tasks in severely adverse conditions such as loss, noise and dephasing can be improved by illumination with quantum states of light. Previous results have shown a modest reduction in the number of measurements necessary to achieve a given precision. Here, we compare three illumination strategies for estimating the relative phase in a noisy, lossy interferometer. When including a common phase fluctuation in the noise processes, we show that using an entangled probe achieves an advantage in parameter estimation precision that scales with the number of entangled modes. This work provides a theoretical foundation for the use of highly multimode entangled states of light for practical measurement tasks in experimentally challenging conditions.