Quantum phases in $p$-orbital degenerated attractive 1D fermionic optical lattices

摘要

We examine quantum phases emerged by double degeneracy of $p$-orbital bandsin attractive atomic Fermi gases loaded on a 1D optical lattice. Our numericalsimulations by the density-matrix renormalization group predict the emergenceof a state with a charge excitation gap, the Haldane insulator phase. A mappingonto an effective spin-$1$ model reveals its physical origin. Moreover, we showthat population imbalance leads to richer diversity of the quantum phases,including a phase-separated polarized state. Finally, we study the effects ofharmonic trap potential in this 1D chain.