title: High spin systems with orbital degeneracy.
abstract: High-spin systems with orbital degeneracy are studied in the large spin limit. In the absence of Hund's coupling, the classical spin model is mapped onto disconnected orbital systems with spins up and down, respectively. The ground state of the isotropic model is an orbital valence bond state where each bond is an orbital singlet with parallel spins, and neighboring bonds interact antiferromagnetically. Possible relevance to the transition metal oxides is discussed.
authors.affiliation: Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Shun-Qing
authors.initials: SQ
authors.lastname: Shen
authors.forename: X C
authors.initials: XC
authors.lastname: Xie
authors.forename: F C
authors.initials: FC
authors.lastname: Zhang