Effects of Orbital Degeneracy and Electron Correlation on Charge Dynamics in Perovskite Manganese Oxides

Abstract

Taking the orbital degeneracy of $e_g$ conduction bands and the Coulomb interaction into account in a double-exchange model, we investigate charge dynamics of perovskite Mn oxides by the Lancz$\ddot{\mathrm{o}}$s diagonalization method. In the metallic phase near the Mott insulator, it is found that the optical conductivity for a spin-polarized two-dimensional system exhibits a weight transfer to a broad and incoherent structure within the lower-Hubbard band together with a suppressed Drude weight. It reproduces qualitative feature of the experimental results. As an orbital effect, we find that an anomalous charge correlation at quarter filling suppresses the coherent charge dynamics and signals precursor to the charge ordering.

4 pages LaTeX including 3 PS figures, to appear in J. Phys. Soc. Jpn

References in corpus (3)

• Optical conductivity of colossal magnetorestistance compounds: Role of orbital degeneracy in the ferromagnetic phase
• Optical Conductivity of the Two-Dimensional Hubbard Model
• Effects of Electron Correlation, Orbital Degeneracy and Jahn-Teller Coupling in Perovskite Manganites

Cited by in corpus (5)

• Resonant X-ray Scattering in Manganites - Study of Orbital Degree of Freedom -
• Ordering and Fluctuation of Orbital and Lattice Distortion in Perovskite Manganese Oxides
• Incoherent Charge Dynamics in Perovskite Manganese Oxides
• Correlation Effects on the Double Exchange Model in a Ferromagnetic Metallic Phase
• Phase diagram of a generalized Hubbard model applied to orbital order in manganites