Dynamical arrest of ultracold lattice fermions

TL;DR

This paper explores how strong correlations cause dynamical arrest in ultracold lattice fermions, affecting cloud size and expansion behavior, with implications for understanding non-equilibrium effects in quantum gases.

Contribution

It provides a theoretical analysis of the interplay between thermodynamics and strong correlations, revealing dynamical arrest phenomena in ultracold fermionic systems.

Findings

Qualitative agreement with experimental anomalous expansion

Quantitative agreement only at weak interactions

Identification of non-equilibrium effects due to dynamical arrest

Abstract

We theoretically investigate the thermodynamics of an interacting inhomogeneous two-component Fermi gas in an optical lattice. Motivated by a recent experiment by L. Hackerm\"uller et al., Science, 327, 1621 (2010), we study the effect of the interplay between thermodynamics and strong correlations on the size of the fermionic cloud. We use dynamical mean-field theory to compute the cloud size, which in the experiment shows an anomalous expansion behavior upon increasing attractive interaction. We confirm this qualitative effect but, assuming adiabaticity, we find quantitative agreement only for weak interactions. For strong interactions we observe significant non-equilibrium effects which we attribute to a dynamical arrest of the particles due to increasing correlations.