Similarities and Differences between LaNiO 2 and CaCuO 2 and Implications for Superconductivity

• Published in: Physical review. X Vol. 10; no. 1
• Main Authors: Botana, A. S., Norman, M. R.
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 04-02-2020
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
• ISSN: 2160-3308; 2160-3308
• DOI: 10.1103/PhysRevX.10.011024

The recent observation of superconductivity in hole-doped NdNiO2 has generated considerable attention. The similarities and differences between this infinite-layer nickelates and cuprates are still an open question. To address this issue we derive, via-principles calculations, essential facts related to the electronic structure and magnetism of R NiO2 (R = La , Nd) in comparison to their cuprate analog CaCuO2. From this detailed comparison, we find that R NiO2 are promising as cuprate analogs. Besides the much larger d-p energy splitting, and the presence of R 5d states near the Fermi energy in the parent compound, all other electronic-structure parameters seem to be favorable in the context of superconductivity as inferred from the cuprates. In particular, the large value of the longer-range hopping t' and the eg energy splitting are similar to those obtained in cuprates. Doping further acts to increase the cupratelike character of these nickelates by suppressing the self-doping effect of the R 5d bands.