# Ising Antiferromagnet in the 2D Hubbard Model with Mismatched Fermi Surfaces

## TL;DR

This paper investigates the phase diagram of a 2D Hubbard model with spin-dependent anisotropic hopping, revealing the emergence of Ising antiferromagnetic order at infinitesimal interactions and providing critical temperature predictions using advanced quantum Monte Carlo methods.

## Contribution

It provides the first unbiased predictions of critical temperatures for Ising antiferromagnetism in this model using multiple state-of-the-art quantum Monte Carlo techniques.

## Key findings

- Ising antiferromagnetic order appears at infinitesimal repulsive interactions.
- Critical temperatures are predicted for various interaction strengths.
- Results are relevant for ultracold atom experiments with spin-dependent lattices.

## Abstract

We study the phase diagram of the two-dimensional repulsive Hubbard model with spin-dependent anisotropic hopping at half-filling. The system develops Ising antiferromagnetic long-range order already at infinitesimal repulsive interaction strength in the ground state. Outside the perturbative regime, unbiased predictions for the critical temperatures of the Ising antiferromagnet are made for representative interaction values by a variety of state-of-the-art quantum Monte Carlo methods, including the diagrammatic Monte Carlo, continuous-time determinantal Monte Carlo and path-integral Monte Carlo methods. Our findings are relevant to ultracold atom experiments in the p-orbital or with spin-dependent optical lattices.