  Numerical simulations of Ramsey fringe formation in double Bose condensates
are carried out in two spatial dimensions. The effects of meanfield
nonlinearity and diffusion in the condensates give rise to new features in the
Ramsey fringes, namely spatial variation and an asymmetry between positive and
negative field detunings. We introduce the concept of an effective detuning,
which for moderate interpulse times provides a qualitative understanding of the
new features.
