Structural phase transition, s±-wave pairing, and magnetic stripe order in bilayered superconductor La3Ni2O7 under pressure

• Published in: Nature communications Vol. 15; no. 1; pp. 2470 - 11
• Main Authors: Zhang, Yang, Lin, Ling-Fang, Moreo, Adriana, Maier, Thomas A., Dagotto, Elbio
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/1003; 639/766/119/997; Approximation; Density functional theory; Enthalpy; Fermi surfaces; Group 5A compounds; High pressure; Humanities and Social Sciences; Iron; MATERIALS SCIENCE; Mathematical analysis; multidisciplinary; Nesting; Phase transitions; Science; Science (multidisciplinary); Selenides; Superconductivity; Superconductors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-46622-z

Motivated by the recently discovered high- T c superconductor La 3 Ni 2 O 7 , we comprehensively study this system using density functional theory and random phase approximation calculations. At low pressures, the Amam phase is stable, containing the Y 2− mode distortion from the Fmmm phase, while the Fmmm phase is unstable. Because of small differences in enthalpy and a considerable Y 2− mode amplitude, the two phases may coexist in the range between 10.6 and 14 GPa, beyond which the Fmmm phase dominates. In addition, the magnetic stripe-type spin order with wavevector ( π , 0) was stable at the intermediate region. Pairing is induced in the s ± -wave channel due to partial nesting between the M  = ( π ,  π ) centered pockets and portions of the Fermi surface centered at the X  = ( π , 0) and Y  = (0,  π ) points. This resembles results for iron-based superconductors but has a fundamental difference with iron pnictides and selenides. Moreover, our present efforts also suggest La 3 Ni 2 O 7 is qualitatively different from infinite-layer nickelates and cuprate superconductors. Recently superconductivity with T c of about 80 K was discovered in a bilayer nickelate La 3 Ni 2 O 7 under high pressure. Here the authors report a density functional theory and random phase approximation study of structural and electronic properties as a function of pressure and discuss the pairing mechanism.