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arXiv · 2507.17961

Squeezing enhanced sensing at an exceptional point

Changqing Wang·Deyuan Hu·Silvia Zorzetti·Anna Grassellino·Alexander Romanenko·Zheshen Zhang
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Abstract

Pushing the boundaries of measurement precision is central for sensing and metrology, pursued by nonclassical resources such as squeezing, and non-Hermitian degeneracies with distinct spectral response. Their convergence, however, remains challenging. We find extraordinary enhancement of sensitivity by unifying both effects in a general framework for quantum sensing in open systems. At the parametric oscillation threshold and an exceptional point, the sensing precision exhibits a unique quartic scaling with the perturbation strength. The result generalizes to multimode squeezed-state sensors with higher-order exceptional points catered to various quantum sensing platforms.

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Changqing Wang, Deyuan Hu, Silvia Zorzetti, Anna Grassellino, Alexander Romanenko, Zheshen Zhang. 2025-07-23. Squeezing enhanced sensing at an exceptional point. https://doi.org/10.1103/kmtx-7x9d

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