  Ultrafast pump-probe technique is a powerful tool to understand and
manipulate properties of materials for designing novel quantum devices. An
intense, single cycle terahertz pulse can change the intrinsic properties of
semiconductor quantum dots to have different luminescence. In a hybrid system
of plasmon and exciton, the coherence and coupling between these two degrees of
freedom play an important role on their optical properties. Therefore, we
consider a terahertz pump optical probe experiment in the hybrid systems where
the terahertz pump pulse couples to the exciton degrees of freedom on the
quantum dot. The time resolved photoluminescence of the hybrid system shows
that the response of the characteristic frequency shifts according to the
overlap between the pump and probe pulses. Furthermore, the resonance between
the exciton and plasmons can be induced by the terahertz pump pulse in some
parameter regimes. Our results show the terahertz driven hybrid system can be a
versatile tool for manipulating the material properties and open a new route to
design modern optical devices.
