2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/215053We investigate spin squeezing of a two-mode boson system with a Josephson coupling. An exact relation between the squeezing and the single-particle coherence at the maximal-squeezing time is discovered, which provides a more direct way to measure the squeezing by readout the coherence in atomic interference experiments. We prove explicitly that the strongest squeezing is along the $J_z$ axis, indicating the appearance of atom number-squeezed state. Power laws of the strongest squeezing and the optimal coupling with particle number $N$ are obtained based upon a wide range of numerical simulations.4 figures, revtex4, new refs. are addedOther Condensed MatterAtomic PhysicsQuantum Physicstext