Transversal effects on the ground-state of hard-core dipolar bosons in one-dimensional optical lattices

Polar lattice gases are usually assumed to have an inter-site interaction that decays with the inter-particle distance $r$ as $1/r^3$. However, a loose-enough transversal confinement may strongly modify the dipolar decay in one-dimensional lattices. We show that this modification alters significantly the ground-state properties of hard-core dipolar bosons. For repulsive inter-site interactions, the corrected decay alters the conditions for devil's staircase insulators, affecting significantly the particle distribution in the presence of an overall harmonic confinement. For attractive interactions, it results in a reduction of the critical dipole interaction for the formation of self-bound clusters, and for a marked enhancement of the region of liquefied lattice droplets.