Effect of Hund's exchange on the spectral function of a triply orbital degenerate correlated metal -: art. no. 245115

We present an approach based on the dynamical mean-field theory that is able to give the excitation spectrum of a triply degenerate Hubbard model with a Hund's exchange invariant under spin rotation. The lattice problem can be mapped onto a local Anderson model containing 64 local eigenstates. This local problem is solved by a generalized noncrossing approximation. The influence of Hund's coupling J is examined, in detail, for metallic states close to the metal-insulator transition. The band filling is shown to play a crucial role concerning the effect of J on the low-energy dynamics.