  We theoretically consider an ensemble of quantum dimers placed inside an
optical cavity. We predict two effects: first, an exchange of angular momentum
between the dimers mediated by the emission and re-absorption of the cavity
photons leads to the alignment of dimers. Furthermore, the optical angular
momentum of the vacuum state of the chiral cavity is transferred to the
ensemble of dimers which leads to the synchronous rotation of the dimers at
certain levels of light-matter coupling strength.
