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arXiv · 2511.22248

Enhancing information retrieval in quantum-optical critical systems via quantum measurement backaction

Cheng Zhang·Mauro Cirio·Xin-Qi Li·Pengfei Liang
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Abstract

Continuous monitoring of open quantum-optical systems offers a promising route towards quantum-enhanced estimation precision. In such continuous-measurement-based sensing protocols, the ultimate precision limit is dictated, through the quantum Cram\'er-Rao bound, by the global quantum Fisher information associated with the joint system-environment state. Reaching this limit with established continuous measurement techniques in quantum optics remains an outstanding challenge. Here we present a sensing protocol tailored for open quantum-optical sensors that exhibit dissipative criticality, enabling them to significantly narrow the gap to the ultimate precision limit. Our protocol leverages a previously unexplored interplay between the quantum criticality and the quantum measurement backaction inherent in continuous general-dyne detection. We identify a performance sweet spot, near which the ultimate precision limit can be efficiently approached. Our protocol establishes a new pathway towards quantum-enhanced precision in open quantum-optical setups and can be extended to other sensor designs featuring similar dissipative criticality.

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Cheng Zhang, Mauro Cirio, Xin-Qi Li, Pengfei Liang. 2025-11-27. Enhancing information retrieval in quantum-optical critical systems via quantum measurement backaction. https://arxiv.org/abs/2511.22248

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