Authors: A. Kauch and K. Byczuk
Journal:
in "Quantum magnetism", Proc. of the NATO Advanced Study Institute on Quantum Magnetism, Les Houes, France, ed. B. Barbara, Y. Imry, G. Sawatzky, P.C.E. Stamp (Springer, 2008),
p.85.
The local moment approach (LMA) of Logan {\it et al.} and its modification is summarized here. The existence of the local moments is taken from the outset and their values are determined through variational principle by minimizing the corresponding ground state energy. The LMA is used to solved a multi-orbital single impurity Anderson model. The method is also applied to solve the dynamical mean-field equations for the multi-orbital Hubbard model. In particular, the Mott-Hubbard metal--insulator transition is addressed within this approach.