Phase-diffusion dynamics in weakly coupled Bose-Einstein condensates

We study the phase-sensitivity of collisional phase-diffusion between weakly coupled Bose-Einstein condensates, using a semiclassical picture of the two-mode Bose-Hubbard model. When weak-coupling is allowed, zero relative phase locking is attained in the Josephson-Fock transition regime, whereas a $\pi$ relative phase is only locked in Rabi-Josephson point. Our analytic semiclassical estimates agree well with the numerical results.