2 research outputs found
Kinks in the electronic dispersion of the Hubbard model away from half filling
We study kinks in the electronic dispersion of a generic strongly correlated
system by dynamic mean-field theory (DMFT). The focus is on doped systems away
from particle-hole symmetry where valence fluctuations matter potentially.
Three different algorithms are compared to asses their strengths and
weaknesses, as well as to clearly distinguish physical features from
algorithmic artifacts. Our findings extend a view previously established for
half-filled systems where kinks reflect the coupling of the fermionic
quasiparticles to emergent collective modes, which are identified here as spin
fluctuations. Kinks are observed when strong spin fluctuations are present and,
additionally, a separation of energy scales for spin and charge excitations
exists. Both criteria are met by strongly correlated systems close to a
Mott-insulator transition. The energies of the kinks and their doping
dependence fit well to the kinks in the cuprates, which is surprising in view
of the spatial correlations neglected by DMFT.Comment: 13 pages, 15 figure
Dynamical Mean Field within Iterative Perturbation Theory
We consider the iterative-perturbation theory and its generalization to multi-orbital Hubbard models. We discuss in detail all aspects of numerical implementations of the method