Superfluid density and quasi-long-range order in the one-dimensional disordered Bose-Hubbard model

TL;DR

This paper investigates the superfluid to Bose glass transition in the one-dimensional disordered Bose-Hubbard model using advanced tensor network methods, accurately locating critical points and exploring uncharted parameter regimes.

Contribution

It introduces a gauge-adaptive tree tensor network approach for periodic systems and maps the phase boundary in strong disorder and weak interactions regimes.

Findings

Accurate critical points for superfluid to glass transition.

Agreement with previous Monte Carlo results in certain regimes.

New insights into the phase boundary in weakly interacting, strongly disordered regimes.

Abstract

We study the equilibrium properties of the one-dimensional disordered Bose-Hubbard model by means of a gauge-adaptive tree tensor network variational method suitable for systems with periodic boundary conditions. We compute the superfluid stiffness and superfluid correlations close to the superfluid to glass transition line, obtaining accurate locations of the critical points. By studying the statistics of the exponent of the power-law decay of the correlation, we determine the boundary between the superfluid region and the Bose glass phase in the regime of strong disorder and in the weakly interacting region, not explored numerically before. In the former case our simulations are in agreement with previous Monte Carlo calculations.