  In this review, we briefly overview recent works on hybrid (nano)
opto-mechanical systems that contain both mechanical oscillators and diamond
nitrogen-vacancy (NV) centers. We review two different types of mechanical
oscillators. The first one is a clamped mechanical oscillator, such as a
cantilever, with a fixed frequency. The second one is an optically trapped
nano-diamond with a build-in nitrogen-vacancy center. By coupling mechanical
resonators with electron spins, we can use the spins to control the motion of
mechanical oscillators. For the first setup, we discuss two different coupling
mechanisms which are magnetic coupling and strain induced coupling. We
summarize their applications such as cooling the mechanical oscillator,
generating entanglements between NV centers, squeezing spin ensembles and et
al. For the second setup, we discuss how to generate quantum superposition
states with magnetic coupling, and realize matter wave interferometer. We will
also review its applications as ultra-sensitive mass spectrometer. Finally, we
discuss new coupling mechanisms and applications of the field.
