Phase diagram of the extended Bose Hubbard model

TL;DR

This paper uses the Density Matrix Renormalization Group method to precisely map the phase diagram of a one-dimensional extended Bose Hubbard model, identifying various quantum phases and their boundaries.

Contribution

It provides an accurate determination of phase boundaries and distinguishes between Mott, density-wave, and Haldane insulator phases in the model.

Findings

Identified phase boundaries between superfluid and insulating phases.

Distinguished between Mott, density-wave, and Haldane insulator phases.

Confirmed the existence of the Haldane insulator with string order.

Abstract

By means of the Density Matrix Renormalization Group technique, we accurately determine the zero-temperature phase diagram of the one-dimensional extended Bose Hubbard model with on-site and nearest-neighbor interactions. We analyze the scaling of the charge and of the neutral ground-state energy gaps, as well as of various order parameters. In this way we come to an accurate location of the boundaries between the superfluid and the insulating phases. In this last region we are able to distinguish between the conventional Mott insulating and density-wave phases, and the Haldane Insulator phase displaying long-range string ordering, as originally predicted by E.G. Dalla Torre, E. Berg and E. Altman in Phys. Rev. Lett. 97, 260401 (2006).