Thursday, March 22, 2012

1203.4658 (Andrii Sotnikov et al.)

Advantages of mass-imbalanced ultracold fermionic mixtures for
approaching quantum magnetism in optical lattices
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Andrii Sotnikov, Daniel Cocks, Walter Hofstetter
We study magnetic phases of two-component mixtures of ultracold fermions with repulsive interactions in optical lattices in the presence of hopping imbalance. Our analysis is based on dynamical mean-field theory (DMFT) and its real-space generalization at finite temperature. We study the temperature dependence of the transition into the ordered state as a function of the interaction strength and the imbalance parameter in two and three spatial dimensions. We show that below the critical temperature for Neel order mass-imbalanced mixtures also exhibit a charge-density wave, which provides a directly observable signature of the ordered state. For the trapped system, we compare our results obtained by real-space DMFT to a local-density approximation. We calculate the entropy for a wide range of parameters and identify regions, in which mass-imbalanced mixtures have clear advantages over balanced mixtures for the purpose of obtaining and detecting quantum magnetism.
View original: http://arxiv.org/abs/1203.4658

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