Regensburg 2013 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 51: Correlated Electrons: General Theory 1
TT 51.5: Vortrag
Donnerstag, 14. März 2013, 10:30–10:45, H6
Effective crystal field and Fermi surface topology in correlated multi-orbital systems — Nico Parragh1, Giorgio Sangiovanni1, Philipp Hansmann2, Stefan Hummel3, Karsten Held3, and •Alessandro Toschi3 — 1Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Germany — 2Centre de Physique Théorique, Ècole Polytechnique, France — 3Institut für Festkörperphysik, Technische Universität Wien, Austria
The electronic correlation effect of enhancing/reducing
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. Consequently, an accurate theoretical prediction of the Fermi surface structure is a very desirable goal, in
particular for the emerging field of engineering new correlated heterostructures. In this respect, however, the application of one of the most powerful ab-initio scheme, i.e. the merger between the local density approximation (LDA) and the dynamical mean field theory (DMFT), can give contractdicting results:
In recent studies of Ni-based heterostructure, the predicted Fermi surface is totally different depending on whether less correleated p orbitals are or are not included in the calculation[1,2]. The LDA+DMFT model study we present here aims at a clarifying the origin of this problem and at identifying the key parameters, which control the Fermi surface properties of these systems.
[1] P. Hansmann, A. Toschi, Xiaoping Yang, O.K. Andersen, and K. Held, Phys. Rev. B 82, 235123 (2010)
M. J. Han, Xin Wang, C. A. Marianetti, and A. J. Millis,
Phys. Rev. Lett. 107, 206804 (2011).