Numerical study of the hard-core Bose-Hubbard Model on an Infinite Square Lattice

TL;DR

This paper uses the infinite PEPS algorithm to analyze the hard-core Bose-Hubbard model on an infinite square lattice, accurately reproducing known results and exploring entanglement, correlations, and phase transitions.

Contribution

It applies the infinite PEPS method to comprehensively study the phase diagram and properties of the hard-core Bose-Hubbard model at zero temperature.

Findings

Accurate ground state energy, particle density, and condensate fraction across the phase diagram.

Analysis of ground state entanglement and two-point correlators.

Fidelity-based phase diagram analysis and response to perturbations.

Abstract

We present a study of the hard-core Bose-Hubbard model at zero temperature on an infinite square lattice using the infinite Projected Entangled Pair State algorithm [Jordan et al., Phys. Rev. Lett. 101, 250602 (2008)]. Throughout the whole phase diagram our values for the ground state energy, particle density and condensate fraction accurately reproduce those previously obtained by other methods. We also explore ground state entanglement, compute two-point correlators and conduct a fidelity-based analysis of the phase diagram. Furthermore, for illustrative purposes we simulate the response of the system when a perturbation is suddenly added to the Hamiltonian.