Quantum-enhanced estimation of signal field amplitudes with critical squeezed states of photonic modes

Quantum Physics [Submitted on 28 Mar 2026] Quantum-enhanced estimation of signal field amplitudes with critical squeezed states of photonic modes Ken Chen, Jia-Hao Lv, Wen Ning, Zhen-Biao Yang, Shi-Biao Zheng Critical phenomena of quantum systems offer a promising strategy to improve measurement precision. So far, many criticality-enhanced quantum metrological schemes have been proposed by using the adiabatically evolved photonic states of composite systems involving a qubit and a field interacting with each other. These schemes focus on the measurement of the system's inherent frequencies. We here propose a criticality-enhanced quantum sensing protocol, aiming to estimate the amplitude of an external signal field with the interacting qubit-photon system. The signal field is coupled to the photonic mode, so that the composite system has a unique dark state, where the photonic mode follows a squeezed vacuum state. The information about the signal field amplitude is encoded in one quadrature of the quantized photonic mode, which exhibits a divergent behavior near the critical point. The measurement precision can approach the Heisenberg limit with respect to the time to encode the signal and the photon number of the field mode. Comments: 8 pages, 2 figures Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.27100 [quant-ph]   (or arXiv:2603.27100v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.27100 Focus to learn more Submission history From: Ken Chen [view email] [v1] Sat, 28 Mar 2026 02:40:01 UTC (141 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)