Dresden 2020 – wissenschaftliches Programm
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TT 20.7: Vortrag
Dienstag, 17. März 2020, 12:30–12:45, HSZ 03
Role of interface polarity in the electronic reconstruction of infinite-layer vs. perovskite nickelate films on SrTiO3(001) — •Benjamin Geisler and Rossitza Pentcheva — Fakultät für Physik, Universität Duisburg-Essen, 47057 Duisburg
Motivated by the recent observation of superconductivity in the infinite-layer nickelate NdNiO2 on SrTiO3(001) by Li et al. , we explore the effect of interface polarity on the electronic properties of NdNiOn/SrTiO3(001) and LaNiOn/SrTiO3(001) thin films (n = 2,3) by performing first-principles calculations including a Coulomb repulsion term. For infinite-layer nickelate films (n = 2), electronic reconstruction drives the emergence of a two-dimensional electron gas (2DEG) at the interface due to a strong occupation of the Ti 3d states. This effect is more pronounced than in the paradigmatic LaAlO3/SrTiO3(001) system and accompanied by a substantial reconstruction of the Fermi surface. We contrast our findings with results for the perovskite compounds (n = 3). Moreover, we analyze the topotactic reaction from a perovskite to an infinite-layer heterostructure and show why the reduction is confined to the nickelate film, whereas the SrTiO3 substrate remains intact.
Funding by the DFG within TRR 80 (G3) is acknowledged.
 D. Li et al., Nature 572, 624 (2019)