  We investigate the dynamical properties for non-Hermitian triple-well system
with a loss in the middle well. When chemical potentials in two end wells are
uniform and nonlinear interactions are neglected, there always exists a dark
state, whose eigenenergy becomes zero, and the projections onto which do not
change over time and the loss factor. The increasing of loss factor only makes
the damping form from the oscillating decay to over-damping decay. However,
when the nonlinear interaction is introduced, even interactions in the two end
wells are also uniform, the projection of the dark state will be obviously
diminished. Simultaneously the increasing of loss factor will also aggravate
the loss. In this process the interaction in the middle well plays no role.
When two chemical potentials or interactions in two end wells are not uniform
all disappear with time. In addition, when we extend the triple-well system to
a general (2n + 1)-well, the loss is reduced greatly by the factor 1=2n in the
absence of the nonlinear interaction.
