Interaction-Induced Fractionalization and Topological Superconductivity in the Polar Molecules Anisotropic t-J Model

We show that the interplay between antiferromagnetic interaction and hole motion gives rise to a topological superconducting phase. This is captured by the one dimensional anisotropic t-J model which can be experimentally achieved with ultracold polar molecules trapped onto an optical lattice. As a function of the anisotropy strength we find that different quantum phases appear, ranging from a gapless Luttinger liquid to spin gapped conducting and superconducting regimes. In the presence of appropriate z anisotropy, we also prove that a phase characterized by nontrivial topological order takes place. The latter is described uniquely by a finite nonlocal string parameter and presents robust edge spin fractionalization. These results allow us to explore quantum phases of matter where topological superconductivity is induced by the interaction.