Berlin 2024 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 5: Nickelates I
TT 5.10: Talk
Monday, March 18, 2024, 12:00–12:15, H 3007
Strong orbital- and momentum-dependent correlation effects in an infinite-layer NdNiO2 — •Evgeny Stepanov1, Matteo Vandelli2, Alexander Lichtenstein2, and Frank Lechermann3 — 1École polytechnique, France — 2Universität Hamburg, Germany — 3Ruhr-Universität Bochum, Germany
Layered nickel-oxide compounds have garnered significant attention since the discovery of superconductivity in this class of materials. The physical properties of layered nickelates originate from a complex interplay between strong local Coulomb correlations, spatial collective electronic fluctuations, orbital degrees of freedom, and a non-trivial band structure. Until now, even the most advanced numerical calculations could not account for all these important effects simultaneously.
In this talk we present results of accurate many-body D-TRILEX calculations for the layered NdNiO2 compound at stoichiometry and upon hole doping [arXiv:2311.09983 (2023)] performed in the framework of an ab-initio three-orbital model. Our calculations demonstrate that both spatial collective electronic fluctuations and orbital degrees of freedom are equally important. Considering both these effects in a self-consistent manner results in a strong momentum- and orbital-dependent renormalization of the electronic spectral function. This renormalization favors the formation of the charge density wave ordering, which originates from the intraband correlations within the Ni-dz2 orbital. We also find that the system displays strong antiferromagnetic fluctuations that stem from the Ni-dx2−y2 orbital.
Keywords: nickelates; many-body effects; electronic spectral function; charge density wave; antiferromagnetism