Polar bosons in one-dimensional disordered optical lattices

TL;DR

This paper investigates how disorder influences the phases of ultra-cold polar bosons in one-dimensional optical lattices, revealing complex phase transitions and the emergence of novel insulating states.

Contribution

It provides a detailed analysis of disorder effects on polar bosons, identifying new phase connections and the conditions for different insulating phases in disordered optical lattices.

Findings

Disorder induces a Haldane-insulator phase with finite parity order.

Weak disorder transforms the density-wave phase into a Bose-glass.

Quasi-disorder connects the Haldane insulator with a gapped incommensurate density wave.

Abstract

We analyze the effects of disorder and quasi-disorder on the ground-state properties of ultra-cold polar bosons in optical lattices. We show that the interplay between disorder and inter-site interactions leads to rich phase diagrams. A uniform disorder leads to a Haldane-insulator phase with finite parity order, whereas the density-wave phase becomes a Bose-glass at very weak disorder. For quasi-disorder, the Haldane insulator connects with a gapped generalized incommesurate density wave without an intermediate critical region.