Correlated interface electron gas in infinite-layer nickelate versus cuprate films on SrTiO${}_3$(001)

Abstract

Based on first-principles calculations including a Coulomb repulsion term, we identify trends in the electronic reconstruction of $A$NiO${}_2$/SrTiO${}_3$(001) ($A=$ Pr, La) and $A$CuO${}_2$/SrTiO${}_3$(001) ($A=$ Ca, Sr). Common to all cases is the emergence of a quasi-two-dimensional electron gas (q2DEG) in SrTiO${}_3$(001), albeit the higher polarity mismatch at the interface of nickelates vs. cuprates to the nonpolar SrTiO${}_3(001)$ substrate ($3+/0$ vs. $2+/0$) results in an enhanced q2DEG carrier density. The simulations reveal a significant dependence of the interfacial Ti $3d_{xy}$ band bending on the rare-earth ion in the nickelate films, being $20$-$30\%$ larger for PrNiO${}_2$ and NdNiO${}_2$ than for LaNiO${}_2$. Contrary to expectations from the formal polarity mismatch, the electrostatic doping in the films is twice as strong in cuprates as in nickelates. We demonstrate that the depletion of the self-doping rare-earth $5d$ states enhances the similarity of nickelate and cuprate Fermi surfaces in film geometry, reflecting a single hole in the Ni and Cu $3d_{x^2-y^2}$ orbitals. Finally, we show that NdNiO${}_2$ films grown on a polar NdGaO${}_3(001)$ substrate feature a simultaneous suppression of q2DEG formation as well as Nd~$5d$ self-doping.

10 pages, 5 figures

References in corpus (13)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• A superconducting praseodymium nickelate with infinite layer structure
• Late transition-metal oxides with infinite-layer structure: Nickelates versus cuprates
• Role of $4f$ states in infinite-layer NdNiO${}_2$
• Electronic structure of rare-earth infinite-layer ReNiO2 (Re=La, Nd)
• Materials design of dynamically stable $d^9$ layered nickelates
• Fluctuation-frustrated flat band instabilities in NdNiO2
• First-principles study of the mobility of SrTiO${}_3$
• Design of $n$- and $p$-type oxide thermoelectrics in LaNiO${}_3$/SrTiO${}_3(001)$ superlattices exploiting interface polarity
• Prediction of thickness limits of ideal polar ultrathin films

Cited by in corpus (3)

• Thin-film aspects of superconducting nickelates
• Coupling of electronic and structural degrees of freedom in vanadate superlattices
• Quasiparticle approach to the transport in infinite-layer nickelates