Authors: Y. Ono, R. Bulla, and M. Potthoff
Journal:
Physica B 329, 942 (2003)
The Mott metal-insulator transition in the multi-band Hubbard model in infinite dimensions is studied by using the linearized dynamical mean-field theory. The critical interaction for the metal-insulator transition is obtained analytically. For the symmetric case with the orbital degeneracy M, the critical value is found to be given by Uc=(4M+2)\sqrt{L2}, where L2 is the second moment of the non-interacting density of states. We also derive an analytic expression for the discontinuity in the chemical potential in the change from hole to electron doping, for U larger than the critical value Uc. The results are in good agreement with the numerical results obtained from the exact diagonalization method.