Quantum metrology uses non-classical states, such as Fock states, to enhance measurement precision beyond classical limits. This paper demonstrates an efficient method for generating large Fock states (approaching 100 photons) in a superconducting microwave cavity using a programmable photon number filter. These states are then used in displacement and phase measurements, achieving quantum-enhanced metrology approaching Heisenberg scaling and a maximum metrological gain of up to 14.8 dB. The method is potentially applicable to other systems, promising advancements in weak force detection and dark matter searches.

Xiaowei Deng, Sai Li, Zi-Jie Chen, Zhongchu Ni, Yanyan Cai, Jiasheng Mai, Libo Zhang, Pan Zheng, Haifeng Yu, Chang-Ling Zou, Song Liu, Fei Yan, Yuan Xu, Dapeng Yu