  A deterministic scheme for generating a macroscopic superposition state of a
nanomechanical resonator is proposed. The nonclassical state is generated
through a suitably engineered dissipative dynamics exploiting the
optomechanical quadratic interaction with a bichromatically driven optical
cavity mode. The resulting driven dissipative dynamics can be employed for
monitoring and testing the decoherence processes affecting the nanomechanical
resonator under controlled conditions.
