  Spin-1 Bose gases quenched to spin degeneracy exhibit fragmentation: the
appearance of a condensate in more than one single-particle state. Due to its
highly entangled nature, the dynamics leading to this collective state are
beyond the scope of a Gaussian variational approximation of the many-body wave
function. Here, we improve the performance of the Gaussian variational Ansatz
by considering dissipation into a fictitious environment, effectively
suppressing entanglement within individual quantum trajectories at the expense
of introducing a classical mixture of states. We find that this quantum
trajectory approach captures the dynamical formation of a fragmented
condensate, and analyze how much dissipation should be added to the experiment
in order to keep a single realization in a non-fragmented state.
