title: Correlation-Driven Topological Fermi Surface Transition in FeSe.
abstract: The electronic structure and phase stability of paramagnetic FeSe is computed by using a combination of ab initio methods for calculating band structure and dynamical mean-field theory. Our results reveal a topological change (Lifshitz transition) of the Fermi surface upon a moderate expansion of the lattice. The Lifshitz transition is accompanied with a sharp increase of the local moments and results in an entire reconstruction of magnetic correlations from the in-plane magnetic wave vector, (π,π) to (π,0). We attribute this behavior to a correlation-induced shift of the van Hove singularity originating from the d(xy) and d(xz)/d(yz) bands at the M point across the Fermi level. We propose that superconductivity is strongly influenced, or even induced, by a van Hove singularity.
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Augsburg 86135, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Leonov
authors.affiliation: Institute of Metal Physics, Sofia Kovalevskaya Street 18, 620990 Yekaterinburg GSP-170, Russia.|Ural Federal University, 620002 Yekaterinburg, Russia.
authors.forename: S L
authors.initials: SL
authors.lastname: Skornyakov
authors.affiliation: Institute of Metal Physics, Sofia Kovalevskaya Street 18, 620990 Yekaterinburg GSP-170, Russia.|Ural Federal University, 620002 Yekaterinburg, Russia.
authors.forename: V I
authors.initials: VI
authors.lastname: Anisimov
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Augsburg 86135, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Vollhardt