Bosonic superfluid-insulator transition in continuous space

TL;DR

This paper introduces a hybrid quantum Monte Carlo method to study the zero-temperature phase diagram of interacting Bose gases in optical lattices, revealing the superfluid-insulator transition beyond the single-band Bose-Hubbard model.

Contribution

A novel hybrid quantum Monte Carlo approach that combines continuous space and lattice algorithms to analyze Bose gases in optical lattices beyond traditional models.

Findings

Identified critical interaction strength and lattice intensity for the superfluid-insulator transition.

Explored shallow lattice and strong interaction regimes.

Discussed implications for super-solid states of matter.

Abstract

We investigate the zero-temperature phase diagram of interacting Bose gases in the presence of a simple cubic optical lattice, going beyond the regime where the mapping to the single-band Bose-Hubbard model is reliable. Our computational approach is a new hybrid quantum Monte Carlo method which combines algorithms used to simulate homogeneous quantum fluids in continuous space with those used for discrete lattice models of strongly correlated systems. We determine the critical interaction strength and optical lattice intensity where the superfluid-to-insulator transition takes place, considering also the regime of shallow optical lattices and strong inter-atomic interactions. The implications of our findings for the super-solid state of matter are discussed.