Ultralong-range order in the Fermi-Hubbard model with long-range interactions

TL;DR

This paper uncovers a new ultralong-range ordered phase in the Fermi-Hubbard model with long-range dipole interactions using large-scale finite-temperature simulations, relevant for ultracold atom experiments.

Contribution

It introduces the existence of an ultralong-range ordered phase in the Fermi-Hubbard model with long-range interactions, demonstrated through large-scale numerical calculations.

Findings

Discovery of an ultralong-range ordered phase

Non-trivial density correlation behavior on large scales

Experimental accessibility with ultracold polar molecules

Abstract

We use the dual boson approach to reveal the phase diagram of the Fermi-Hubbard model with long-range dipole-dipole interactions. By using a large-scale finite-temperature calculation on a $64 \times 64$ square lattice we demonstrate the existence of a novel phase, possessing an `ultralong-range' order. The fingerprint of this phase -- the density correlation function -- features a non-trivial behavior on a scale of tens of the lattice sites. We study the properties and the stability of the ultralong-range ordered phase, and show that it is accessible in modern experiments with ultracold polar molecules and magnetic atoms.