Magnetic phases of mass- and population-imbalanced ultracold fermionic mixtures in optical lattices

TL;DR

This paper explores the magnetic phases of ultracold fermionic mixtures in optical lattices with imbalances, revealing diverse magnetic orders and their stability through advanced theoretical modeling.

Contribution

It provides a detailed phase diagram and stability analysis of magnetic phases in imbalanced fermionic mixtures using dynamical mean-field theory.

Findings

Identification of various magnetic orders including antiferromagnetic and ferrimagnetic phases.

Analysis of phase stability against thermal fluctuations.

Quantitative modeling of trapped gases with local density approximation.

Abstract

We study magnetic phases of two-component mixtures of ultracold fermions with repulsive interactions in optical lattices in the presence of both hopping and population imbalance by means of dynamical mean-field theory (DMFT). It is shown that these mixtures can have easy-axis antiferromagnetic, ferrimagnetic, charge-density wave, and canted-antiferromagnetic order or be unordered depending on parameters of the system. We study the resulting phase diagram in detail and investigate the stability of the different phases with respect to thermal fluctuations. We also perform a quantitative analysis for a gas confined in a harmonic trap, both within the local density approximation and using a full real-space generalization of DMFT.