Abstract
We consider the orbital ordering in and similar systems, proceeding from the band picture. We show that for a realistic magnetic structure of type there exists a complete nesting between two bands. As a result there occurs an instability toward an excitonic insulatorlike state—an electron-hole pairing with the wave vector , which opens a gap in the spectrum and makes the system insulating. In the resulting state there appears an orbital ordering, the orbital density wave, the type of which coincides with those existing in .
- Received 4 March 2005
DOI:https://doi.org/10.1103/PhysRevB.72.012402
©2005 American Physical Society