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Spin-Charge-Density Wave in a Squircle-Like Fermi Surface for Ultracold Atoms



Ian B. Spielman, Dima Makogon, Christiane de Morais Smith


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) x SO(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.
Physical Review Letters


charge density wave, exotic bands structure, Fermions, nesting, Optical lattice, spin density wave


Spielman, I. , Makogon, D. and de, C. (2012), Spin-Charge-Density Wave in a Squircle-Like Fermi Surface for Ultracold Atoms, Physical Review Letters, [online], (Accessed July 20, 2024)


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Created January 20, 2012, Updated November 10, 2018