The magnetic and orbital structures in manganese oxides with perovskite structure are examined by using the exact diagonalization method on finite-size clusters. The orbital degeneracy in the eg states is taken into account based on the effective Hamiltonian derived in the insulating state with strong Coulomb interaction. It is shown that A-, C- and G-type antiferromagnetic orderings occur as a result of competition or cooperation of the superexchange interaction of t2g spins and the coupling between spins and orbitals. The spin and orbital excitations are also examined.
- Exact diagonalization
- Spin and orbital wave
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering