@article{oai:niigata-u.repo.nii.ac.jp:00002264, author = {Ono, Yoshiaki and Ralf, Bulla and Michael, Potthoff}, journal = {Physical Review B, Physical Review B}, month = {}, note = {Mott metal-insulator transitions in an M-fold orbitally degenerate Hubbard model are studied by means of a generalization of the linearized dynamical mean-field theory. The method allows for an efficient and reliable determination of the critical interaction Uc for any integer filling n and different M at zero temperature. For half-filling a linear dependence of Uc on M is found. Inclusion of the (full) Hund's rule exchange J results in a strong reduction of Uc. The transition turns out to change qualitatively from continuous for J=0 to discontinuous for any finite J. This result is confirmed using the exact-diagonalization method for M=2.}, pages = {035119-1--035119-6}, title = {Mott transition in correlated electron systems with orbital degree of freedom}, volume = {67}, year = {2003} }