Abstract
In order to clarify a crucial role of orbital degree of freedom in geometrically frustrated systems, we investigate both ground- and excited-state properties of the -orbital degenerate Hubbard model on two kinds of lattices, ladder and zigzag chain, by using numerical techniques. In the ladder, spin correlation extends in the whole system, while the zigzag chain is decoupled to a double chain and spin excitation is confined in one side of the double chain due to the selection of a specific orbital. We envision a kind of self-organization phenomenon that the geometrically frustrated multiorbital system is spontaneously reduced to a one-orbital model to suppress the spin frustration.
- Received 1 October 2004
DOI:https://doi.org/10.1103/PhysRevB.71.180410
©2005 American Physical Society