Competing insulating phases of dipolar bosons in a dimerized optical lattice

TL;DR

This paper investigates the ground state phases of dipolar bosons in a one-dimensional dimerized optical lattice, revealing stable density wave and bond-order density wave phases influenced by lattice dimerization and interactions.

Contribution

It introduces the BODW phase, a novel insulating state with combined bond-order and density wave characteristics, and analyzes its stability under various interactions.

Findings

Stable density wave phase at half filling.

Identification of a bond-order density wave (BODW) phase at quarter filling.

BODW phase robustness increases with stronger hopping dimerization.

Abstract

We study the ground state properties of dipolar bosons in a one dimensional dimerized optical lattice. In the limit of strong onsite repulsion i.e. hardcore bosons, and strong dipole-dipole interaction, a stable density wave (DW) phase is obtained at half filling as a function of lattice dimerization. Interestingly, at quarter filling we obtain the signatures of an insulating phase which has both the character the bond-order (BO) and the DW insulators which we call a bond-order density wave (BODW) phase. Moreover, we show that for a fixed hopping dimerization there occurs a BO-DW phase crossover as a function of the dipole-dipole interaction and the BODW phase is more robust when the hopping dimerization is stronger. We further examine the stability of the BODW phase in the limit of finite onsite interactions.