2007/01/31 by Congjun Wu, Doron L. Bergman, Doron Bergman +2 · 7 citations
Chemistry · Physics and Astronomy · #Atomic orbital #Boson #Chemistry #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Crystal structure #Crystallization #Crystallography #Fermion #Geometry #Homogeneous space #Honeycomb #Lattice (music) #Materials science #Optical lattice #Order (exchange) #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum, superfluid, helium dynamics #Superfluidity #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.99.070401
published as Phys. Rev. Lett. 99, 070401 (2007) · 4 pages, accepted by Phys. Rev. Lett
arxiv created 2007/07/10 · openalex publication_date 2007/08/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We study the ground states of cold atoms in the tight-binding bands built from p orbitals on a two dimensional honeycomb optical lattice. The band structure includes two completely flat bands. Exact many-body ground states with on-site repulsion can be found at low particle densities, for both fermions and bosons. We find crystalline order at n=1/6 with a sqrt[3] x sqrt[3] structure breaking a number of discrete lattice symmetries. In fermionic systems, if the repulsion is strong enough, we find the bonding strength becomes dimerized at n=1/2. Experimental signatures of crystalline order can be detected through the noise correlations in time of flight experiments.