<p>Quantum simulation that combines condensed-matter systems with quantum optical phenomena currently drives intense research efforts, particularly in an attempt to introduce collective quantum correlations. Here we show that confining dipolar excitons in a nanoscopic lattice emulates a version of the Bose–Hubbard model with long-range hopping and nearest-neighbour dipolar repulsions. Long-range hopping is evidenced by the spontaneous build-up of many-body sub-radiance, signalled by an algebraic slowdown of the radiative dissipation of excitons. In addition, we observe a threshold increase in the temporal coherence for only dipolar quantum solids. This suggests that excitons condense in a single sub-radiant state for Mott-like phases. These combine spatial order and collectively extended coherence in a single degree of freedom. Our study shows that nanoscopic exciton arrays provide a platform to design strongly correlated lattice models with long-range correlations.</p>