Accessing the Neel phase of ultracold fermionic atoms in a simple-cubic optical lattice

TL;DR

This paper explores the phase diagram of ultracold fermionic atoms in a simple-cubic optical lattice, focusing on the conditions for observing the Neel antiferromagnetic phase through theoretical models.

Contribution

It combines Hartree and Hubbard model approximations to analyze the Neel phase in different interaction regimes of ultracold fermions in optical lattices.

Findings

Neel phase is most accessible at intermediate lattice strengths and interactions.

The two models agree well in the regime where the Neel phase is likely observable.

Discussion of experimental detection issues for the Neel phase.

Abstract

We examine the phase diagram of a simple-cubic optical lattice half-filled by two species of fermionic atoms with a repulsive s-wave contact interaction. We use the Hartree approximation in the regime of weaker interactions, and a Hubbard model approximation in the Mott insulating phase. The regime where the Neel phase of this system is likely to be most accessible to experiments is at intermediate lattice strengths and interactions, and our two approximations agree fairly well in this regime. We discuss the various issues that may determine where in this phase diagram the Neel phase is first produced and detected experimentally, and analyze the quantum phases that occur in the intermediate lattice strength regime.