Using entanglement to discern phases in the disordered one-dimensional Bose-Hubbard model

TL;DR

This study uses entanglement properties derived from matrix product state methods to map out the phase diagram of the disordered one-dimensional Bose-Hubbard model, identifying various quantum phases.

Contribution

It demonstrates that entanglement measures alone can effectively determine the phase diagram of the disordered Bose-Hubbard model for multiple particle densities.

Findings

Confirmed Mott insulator, superfluid, and Bose glass phases for N/L=1 and 1/2.

Identified a double-lobed superfluid phase with reentrance at N/L=2.

Showed phase diagram can be obtained from entanglement properties during MPS updates.

Abstract

We perform a matrix product state based density matrix renormalisation group analysis of the phases for the disordered one-dimensional Bose-Hubbard model. For particle densities N/L = 1, 1/2 and 2 we show that it is possible to obtain a full phase diagram using only the entanglement properties, which come "for free" when performing an update. We confirm the presence of Mott insulating, superfluid and Bose glass phases when N/L = 1 and 1/2 (without the Mott insulator) as found in previous studies. For the N/L = 2 system we find a double lobed superfluid phase with possible reentrance.