High spin systems with orbital degeneracy

Phys Rev Lett. 2002 Jan 14;88(2):027201. doi: 10.1103/PhysRevLett.88.027201. Epub 2001 Dec 26.

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.