  We consider a quantum Bose fluid confined in a triple well potential in 1D
within the exact N-body Bose-Hubbard model to investigate the phenomena of
intrinsic decoherence and loss of purity. Our study is done by following the
time evolution of one-body properties in an N-particle closed environment. We
do an exhaustive exploration of initial conditions to characterize these
phenomena. Here we illustrate our main findings with a set of relevant Fock and
SU(3) coherent states. Our study shows that signatures of stationarity and
maximal mixing are a direct consequence of the inter-particle interactions in
the closed system and become evident as the number of particles is increased.
This fact is confirmed by quantifying the deviations from stationarity by means
of a matrix norm.
