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

Yang Zhang; Ling-Fang Lin; Adriana Moreo; Thomas A Maier; Elbio Dagotto

doi:10.1038/s41467-024-46622-z

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

Nat Commun. 2024 Mar 19;15(1):2470. doi: 10.1038/s41467-024-46622-z.

Authors

Yang Zhang¹, Ling-Fang Lin², Adriana Moreo^{1

3}, Thomas A Maier⁴, Elbio Dagotto^{5

6}

Affiliations

¹ Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.
² Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA. lflin@utk.edu.
³ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
⁴ Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. maierta@ornl.gov.
⁵ Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA. edagotto@utk.edu.
⁶ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. edagotto@utk.edu.

Abstract

Motivated by the recently discovered high-T_c superconductor La₃Ni₂O₇, 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 La₃Ni₂O₇ is qualitatively different from infinite-layer nickelates and cuprate superconductors.