Itinerant ferromagnetism in an interacting Fermi gas with mass imbalance
Abstract
We study the emergence of itinerant ferromagnetism in an ultra-cold atomic gas with a variable mass ratio between the up and down spin species. Mass imbalance breaks the SU(2) spin symmetry leading to a modified Stoner criterion. We first elucidate the phase behavior in both the grand canonical and canonical ensembles. Secondly, we apply the formalism to a harmonic trap to demonstrate how a mass imbalance delivers unique experimental signatures of ferromagnetism. These could help future experiments to better identify the putative ferromagnetic state. Furthermore, we highlight how a mass imbalance suppresses the three-body loss processes that handicap the formation of a ferromagnetic state. Finally, we study the time dependent formation of the ferromagnetic phase following a quench in the interaction strength.
Keywords
Cite
@article{arxiv.1104.1439,
title = {Itinerant ferromagnetism in an interacting Fermi gas with mass imbalance},
author = {C. W. von Keyserlingk and G. J. Conduit},
journal= {arXiv preprint arXiv:1104.1439},
year = {2012}
}