@article{oai:niigata-u.repo.nii.ac.jp:00002131,
 author = {Sano, Kazuhiro and Ono, Yoshiaki},
 journal = {Journal of the Physical Society of Japan, Journal of the Physical Society of Japan},
 month = {Aug},
 note = {The multi-orbital Hubbard model in one dimension is studied using the numerical diagonalization method. Due to the effect of crystal-field splitting △, the fully polarized ferromagnetism, which is observed in the strong coupling regime, becomes unstable against the partially polarized ferromagnetism when Hund's rule coupling J is smaller than a certain critical value of order of △. In the vicinity of the partially polarized ferromagnetism, the orbital fluctuation develops due to the competition between Hund's rule coupling and crystal-field splitting. The superconducting phase with the Luttinger liquid parameter K_ρ> 1 is observed for the singlet ground state in this region..},
 pages = {1847--1850},
 title = {Ferromagnetism and Superconductivity in the Multi-orbital Hubbard Model : Hund's Rule Coupling versus Crystal-Field Splitting},
 volume = {72},
 year = {2003}
}