  Enforcing a non-classical behavior in mesoscopic systems is important for the
study of the boundaries between quantum and classical world. Recent experiments
have shown that optomechanical devices are promising candidates to pursue such
investigations. Here we consider two different setups where the indirect
coupling between a three-level atom and the movable mirrors of a cavity is
achieved. The resulting dynamics is able to conditionally prepare a
non-classical state of the mirrors by means of projective measurements operated
over a pure state of the atomic system. The non-classical features are
persistent against incoherent thermal preparation of the mechanical systems and
their dissipative dynamics.
