  The optomechanical character of molecules was discovered by Raman about one
century ago. Today, molecules are promising contenders for high-performance
quantum optomechanical platforms because their small size and large
energy-level separations make them intrinsically robust against thermal
agitations. Moreover, the precision and throughput of chemical synthesis can
ensure a viable route to quantum technological applications. The challenge,
however, is that the coupling of molecular vibrations to environmental phonons
limits their coherence to picosecond time scales. Here, we improve the
optomechanical quality of a molecule by several orders of magnitude through
phononic engineering of its surrounding. By dressing a molecule with long-lived
high-frequency phonon modes of its nanoscopic environment, we achieve storage
and retrieval of photons at millisecond time scales and allow for the emergence
of single-photon strong coupling in optomechanics. Our strategy can be extended
to the realization of molecular optomechanical networks.
