Interaction induced fractionalization and topological superconductivity in the polar molecules anisotropic $t-J$ model

TL;DR

This paper demonstrates that in a one-dimensional anisotropic $t-J$ model realized with ultracold polar molecules, interactions induce topological superconductivity characterized by edge spin fractionalization and non-trivial topological order.

Contribution

It reveals how interaction-driven topological superconductivity emerges in an experimentally feasible anisotropic $t-J$ model with ultracold polar molecules.

Findings

Identification of a topological superconducting phase with edge spin fractionalization.

Mapping of quantum phases from Luttinger liquid to spin gapped regimes.

Demonstration of topological order characterized by a non local string parameter.

Abstract

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 presence of appropriate $z$-anisotropy, we also prove that a phase characterized by non-trivial topological order takes place. The latter is described uniquely by a finite non local string parameter and presents robust edge spin fractionalization. These results allow to explore quantum phases of matter where topological superconductivity is induced by the interaction.