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arXiv · 1007.0782

Spin-charge-density wave in a squircle-like Fermi surface for ultracold atoms

D. Makogon·I. B. Spielman·C. Morais Smith
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Abstract

We derive and discuss an experimentally realistic model describing ultracold atoms in an optical lattice including a commensurate, but staggered, Zeeman field. The resulting band structure is quite exotic; fermions in the third band have an unusual rounded picture-frame Fermi surface (essentially two concentric squircles), leading to imperfect nesting. We develop a generalized SO(3,1)xSO(3,1) theory describing the spin and charge degrees of freedom simultaneously, and show that the system can develop a coupled spin-charge-density wave order. This ordering is absent in studies of the Hubbard model that treat spin and charge density separately.

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D. Makogon, I. B. Spielman, C. Morais Smith. 2010-07-05. Spin-charge-density wave in a squircle-like Fermi surface for ultracold atoms. https://doi.org/10.1209/0295-5075%2F97%2F33002

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