Berlin 2024 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 42: Focus Session: Frontiers of Electronic-Structure Theory – Advances in Time-Dependent and Nonequilibrium Ab Initio Methods III
O 42.3: Vortrag
Mittwoch, 20. März 2024, 11:00–11:15, HE 101
Unveiling electronic correlation and many-body effects in the CrMnFeCoNi high-entropy alloy — •David Redka1,2, Marco Caputo5, Trpimir Ivsic3, Heinz Huber2, Hubert Ebert4, J. Hugo Dil3,5, László Forró3,6, and Ján Minár1 — 1University of West Bohemia, Czech Republic — 2Hochschule München, Germany — 3Institute of Physics, EPFL, Switzerland — 4Universität München, Germany — 5Paul Scherrer Institut, Switzerland — 6University of Notre Dame, USA
The impact of electronic correlation effects in the CrMnFeCoNi high-entropy alloy on electronic transport, spectroscopies, and optics is investigated. Here we combine experiments like resonant photoemission, and optical response with DFT calculations utilizing the KKR Green's function method including many-body effects via dynamical mean-field theory (DMFT). Our results show excellent agreement between theory and experiment, particularly for onsite Coulomb interactions, mirroring those in the containing pure elements. Through linear response calculations, we demonstrate the influence of the imaginary part of the self-energy of localized d-band electrons. In terms of electrical resistivity, we confirm the known dominance of chemical and magnetic disorder at low temperatures, whereas at higher temperatures, the DMFT contribution becomes significant. In general, we find that many-body correlation effects especially affect states at higher binding energies, next to the strong band smearing due to chemical disorder, revealing the impact on different material properties and response.
Keywords: linear response; many-body effects; transport; optical conductivity; chemical disorder