2001/11/14 by S. Ishihara, Sumio Ishihara, T. Hatakeyama +3 · 3 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.65.064442
10 pages, 6 figures
arxiv created 2001/11/14 · openalex publication_date 2002/01/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The effective Hamiltonian for perovskite titanates is derived by taking into account the threefold degeneracy of t2g orbitals and the strong electron-electron interactions. The magnetic and orbital ordered phases are studied in the mean-field approximation applied to the effective Hamiltonian. A large degeneracy of the orbital states in the ferromagnetic phase is found in contrast to the case of the doubly degenerate eg orbitals. Lifting of this orbital degeneracy due to lattice distortions and spin-orbit coupling is examined. A general form for the scattering cross section of the resonant x-ray scattering is derived and is applied to the recent experimental results in YTiO3. The spin wave dispersion relation in the orbital ordered YTiO3 is also studied.