  Scattering properties of a single plasm on interacting with three non-equally
spaced quantum dots coupled to one-dimensional surface plasmonic waveguide is
investigated theoretically via the real-space approach. It is demonstrated that
the transmission and reflection of a single plasmon can be switched on or off
by controlling the detuning and changing the interparticle distances between
the quantum dots. By controlling the transition frequencies and interparticle
distances of QDs, one can construct a half-transmitting mirror with three QDs
system. We also showed that controlling the transition frequencies and
interparticle distances of QDs results in the complete transmission peak near
the zero detuning.
