Microscopic lattice for two-dimensional dipolar excitons

We report a two-dimensional artificial lattice for dipolar excitons confined in a GaAs double quantum well. Exploring the regime of large fillings per lattice site, we verify that the lattice depth competes with the magnitude of exciton repulsive dipolar interactions to control the degree of localization in the lattice potential. Moreover, we show that dipolar excitons radiate a narrow-band photoluminescence with a spectral width of a few hundreds of $\ensuremath{\mu}\mathrm{eV}$ at 340 mK, in both localized and delocalized regimes. This makes our device suitable for explorations of dipolar excitons quasicondensation in a periodic potential.