Abstract
A Haldane conjecture is revealed for spin-singlet charge modes in -component fermionic cold atoms loaded into a one-dimensional optical lattice. By means of a low-energy approach and density matrix renormalization group calculations, we show the emergence of gapless and gapped phases depending on the parity of for attractive interactions at half-filling. The analog of the Haldane phase of the spin-1 Heisenberg chain is stabilized for with nonlocal string charge correlation and pseudo-spin-1/2 edge states. At the heart of this even-odd behavior is the existence of a spin-singlet pseudo-spin- operator which governs the low-energy properties of the model for attractive interactions and gives rise to the Haldane physics.
- Received 20 November 2009
DOI:https://doi.org/10.1103/PhysRevB.81.020408
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