Mott insulating phases and magnetism of fermions in a double-well optical lattice

Xin Wang; Qi Zhou; S. Das Sarma

doi:10.1103/physreva.84.061603

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arXiv · 1108.4409

Mott insulating phases and magnetism of fermions in a double-well optical lattice

Xin Wang·Qi Zhou·S. Das Sarma

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Abstract

We theoretically investigate, using non-perturbative strong correlation techniques, Mott insulating phases and magnetic ordering of two-component fermions in a two-dimensional double-well optical lattice. At filling of two fermions per site, there are two types of Mott insulators, one of which is characterized by spin-1 antiferromagnetism below the Neel temperature. The super-exchange interaction in this system is induced by the interplay between the inter-band interaction and the spin degree of freedom. A great advantage of the double-well optical lattice is that the magnetic quantum phase diagram and the Neel temperature can be easily controlled by tuning the orbital energy splitting of the two-level system. Particularly, the Neel temperature can be one order of magnitude larger than that in standard optical lattices, facilitating the experimental search for magnetic ordering in optical lattice systems.

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Xin Wang, Qi Zhou, S. Das Sarma. 2011-11-29. Mott insulating phases and magnetism of fermions in a double-well optical lattice. https://doi.org/10.1103/physreva.84.061603

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