  We demonstrate coupling of a semiconductor quantum dot (QD) to an
optomechanical cavity, mediated by the strain of a nano-mechanical mode. The
device comprises an optomechanical photonic crystal nanobeam in GaAs with
embedded In(Ga)As QDs. The flexural mechanical mode of the device can be
optically driven exploiting the large optomechanical coupling rate of the
cavity. The vibrations generate a time-modulated strain field that shifts the
quantum dot transition energy. We observe that optical driving of the
mechanical mode induces a shift in an excitonic line corresponding to an
estimated vacuum strain coupling rate of 214 kHz. Our approach represents an
important step towards the use of phonons to couple different on-chip quantum
systems.
