N. Parragh, G. Sangiovanni, P. Hansmann, S. Hummel, K. Held, A. Toschi
The effect of electronic correlations to enhance or reduce the effective crystal field in multi-orbital correlated materials can be crucial in determining the topology of the Fermi surface and, hence, the physical properties of these systems. In this respect, recent local density approximation (LDA) plus dynamical mean-field theory (DMFT) studies of Ni-based heterostructure have shown contradicting results, depending on whether the less correlated p-orbitals are included or not. We clarify the origin of this problem and identify the key parameters controlling the Fermi surface properties of these systems. A particularly important one is the filling of the identified d-orbitals: in the dp-calculation this is larger so that Hund's exchange leads to a larger local magnetic moment for the dp-model.
View original:
http://arxiv.org/abs/1303.2099
No comments:
Post a Comment