INTERACTION BETWEEN MAGNETIC IONS IN AN INSULATOR - CASE OF DEGENERATE ORBITALS

Previous formulation of magnetic interactions between ions in an insulator is extended to the case of the degenerate orbitals. The symmetry properties of the system are taken into account correctly in the second quantization scheme by choosing “configuration average” of the Hamiltonian as the unperturbed. The results of Gondaira and Tanabe and of Fuchikami and Ono for the super-exchange interaction and spin dependent electric dipole moment are to be modified appropriately and some new terms to be included when the orbitals involved are degenerate. Expressions of the dipole moment operator for the spin independent as well as dependent transitions are given explicitly. © 1978, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.