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The s$^\pm$-Wave Pairing and the Destructive Role of Apical-Oxygen Deficiencies in La$_3$Ni$_2$O$_7$ Under Pressure
- Source :
- Phys. Rev. Lett. 131, 236002 (2023)
- Publication Year :
- 2023
-
Abstract
- Recently, the bilayer perovskite nickelate La$_3$Ni$_2$O$_7$ has been reported to show evidence of high-temperature superconductivity (SC) under a moderate pressure of about 14 GPa. To investigate the superconducting mechanism, pairing symmetry, and the role of apical-oxygen deficiencies in this material, we perform a random-phase-approximation based study on a bilayer model consisting of the $d_{x^2-y^2}$ and $d_{3z^2-r^2}$ orbitals of Ni atoms in both the pristine crystal and the crystal with apical-oxygen deficiencies. Our analysis reveals an $s^{\pm}$-wave pairing symmetry driven by spin fluctuations. The crucial role of pressure lies in that it induces the emergence of the $\gamma$-pocket, which is involved in the strongest Fermi-surface nesting. We further found the emergence of local moments in the vicinity of apical-oxygen deficiencies, which significantly suppresses the $T_c$. Therefore, it is possible to significantly enhance the $T_c$ by eliminating oxygen deficiencies during the synthesis of the samples.<br />Comment: Accepted by Phys. Rev. Lett
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. Lett. 131, 236002 (2023)
- Publication Type :
- Report
- Accession number :
- edsarx.2307.10144
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevLett.131.236002