2008/01/11 by Erhai Zhao, Wen-Yuan Liu, W. Vincent Liu · 2 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermion #Hamiltonian (control theory) #Lattice (music) #Mott insulator #Optical lattice #Physics #Quantum #Quantum mechanics #Quantum, superfluid, helium dynamics #Superfluidity #Ultracold atom #cond-mat.other #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.100.160403
published as Phys. Rev. Lett. 100, 160403 (2008) · added references, corrected Fig.3
arxiv created 2008/01/11 · openalex publication_date 2008/04/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A gas of strongly interacting single-species (spinless) p-orbital fermionic atoms in 2D optical lattices is proposed and studied. Several interesting new features are found. In the Mott limit on a square lattice, the gas is found to be described effectively by an orbital exchange Hamiltonian equivalent to a pseudospin-1/2 XXZ model. For a triangular, honeycomb, or kagome lattice, the orbital exchange is geometrically frustrated and described by a new quantum 120 degrees model. We determine the orbital ordering on the kagome lattice, and show how orbital wave fluctuations select ground states via the order by disorder mechanism for the honeycomb lattice. We discuss experimental signatures of various orbital ordering.