EN
We review the physics of hybrid optomechanical
systems consisting of a mechanical oscillator interacting
with both a radiation mode and an additional matterlike
system. We concentrate on the cases embodied by either
a single or a multi-atom system (a Bose-Einstein condensate,
in particular) and discuss a wide range of physical
effects, from passive mechanical cooling to the set-up
of multipartite entanglement, from optomechanical nonlocality
to the achievement of non-classical states of a single
mechanical mode. The reviewed material showcases
the viability of hybridised cavity optomechanical systems
as basic building blocks for quantum communication networks
and quantum state-engineering devices, possibly
empowered by the use of quantum and optimal control
techniques. The results that we discuss are instrumental
to the promotion of hybrid optomechanical devices as
promising experimental platforms for the study of nonclassicality
at the genuine mesoscopic level.