  Coupled micro- and nanomechanical oscillators are of fundamental and
technical interest for emerging quantum technologies. Upon interfacing with
long-lived solid-state spins, the coherent manipulation of the quantum hybrid
system becomes possible even at ambient conditions. While, the ability of these
systems to act as a quantum bus inducing long-range spin-spin interactions has
been known, the possibility to coherently couple electron/nuclear spins to the
common modes of multiple oscillators and map their mechanical motion to
spin-polarization has not been experimentally demonstrated. We here report
experiments on interfacing spins to the common modes of a coupled cantilever
system, and show their correlation by translating ultra-low forces induced by
radiation from one oscillator to a distant spin. Further, we analyze the
coherent spin-spin coupling induced by the common modes and estimate the
entanglement generation among distant spins.
