Phases of the one-dimensional Bose-Hubbard model

TL;DR

This paper uses the Density-Matrix Renormalization Group to map the phase diagram of the one-dimensional Bose-Hubbard model, showing no intermediate phase exists between charge density wave and superfluid phases, with reentrant behavior observed.

Contribution

It provides the first comprehensive phase diagram for the 1D Bose-Hubbard model with and without nearest-neighbor interaction, clarifying the nature of phase transitions.

Findings

No intermediate phase between charge density wave and superfluid phases.

Reentrant transition from superfluid to insulator phases.

Complete phase diagrams with and without nearest-neighbor interactions.

Abstract

The zero-temperature phase diagram of the one-dimensional Bose-Hubbard model with nearest-neighbor interaction is investigated using the Density-Matrix Renormalization Group. Recently normal phases without long-range order have been conjectured between the charge density wave phase and the superfluid phase in one-dimensional bosonic systems without disorder. Our calculations demonstrate that there is no intermediate phase in the one-dimensional Bose-Hubbard model but a simultaneous vanishing of crystalline order and appearance of superfluid order. The complete phase diagrams with and without nearest-neighbor interaction are obtained. Both phase diagrams show reentrance from the superfluid phase to the insulator phase.