Metrology using atoms in an array of double-well potentials
Phys. Rev. A 113, 013328 – Published 26 January, 2026
DOI: https://doi.org/10.1103/m3hx-1t2q
Abstract
Quantum effects, such as entanglement, Einstein-Podolsky-Rosen steering, and Bell correlations, can enhance metrological sensitivity beyond the standard quantum limit. These correlations are typically generated through interactions between atoms or molecules, or during the passage of a laser pulse through a birefringent crystal. Here, we consider an alternative method of generating scalable, many-body entangled states, and demonstrate their usability for quantum-enhanced metrology. Our setup is a one-dimensional array of double-well potentials holding independent and uncorrelated Bose-Einstein condensates. The beam-splitting transformation mixes the signal between adjacent wells and yields a strongly entangled state through a many-body equivalent of the Hong-Ou-Mandel effect. We demonstrate that this entanglement can improve the sensitivity of quantum sensors. In our analysis, we account for the effects of atomic fluctuations and identify the optimal measurement that saturates the quantum Cramer-Rao bound.
