Effective orbital ordering in multiwell optical lattices with fermionic atoms
Abstract
We consider the behavior of Fermi atoms on optical superlattices with two-well structure for each node. Fermions on such lattices serve as an analog simulator of the Fermi-type Hamiltonian. We derive a mapping between fermion quantum ordering in the optical superlattices and the spin-orbital physics developed for degenerate d-electron compounds. The appropriate effective spin-orbital model appears to be a modification of the Kugel-Khomskii Hamiltonian. We show how different ground states of this Hamiltonian correspond to particular spin-pseudospin arrangement patterns of fermions on the lattice. The dependence of the fermion arrangement on phases of complex hopping amplitudes is illustrated.
- Publication:
-
Physical Review A
- Pub Date:
- August 2014
- DOI:
- 10.1103/PhysRevA.90.023625
- arXiv:
- arXiv:1405.0543
- Bibcode:
- 2014PhRvA..90b3625B
- Keywords:
-
- 67.85.-d;
- 67.10.Db;
- Ultracold gases trapped gases;
- Fermion degeneracy;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Quantum Physics
- E-Print:
- 7 pages, 2 figures