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arXiv · 2509.00902

Quantum action of the Josephson dynamics

Cesare Vianello·Sofia Salvatore·Luca Salasnich
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Abstract

We study the beyond-mean-field Josephson dynamics of the relative phase between two coupled macroscopic quantum systems. Using a covariant background field method, we derive the one-loop only-phase quantum effective action and the corresponding equation of motion for the quantum average of the phase. These analytical results are benchmarked against the exact quantum dynamics of the two-site Bose-Hubbard model, demonstrating a relevant improvement over the standard mean-field predictions across a wide range of interaction strengths.

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Cesare Vianello, Sofia Salvatore, Luca Salasnich. 2025-08-31. Quantum action of the Josephson dynamics. https://doi.org/10.1007/s10773-025-06186-0

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