返回
Possible s±-wave superconductivity in La3Ni2O7
DOI:10.1103/PhysRevB.108.L140505.png)
摘要
En 中文
Recently, the bulk nickelate La3Ni2O7 is reported to show a signature of high-temperature superconductivity under high pressure above 14 GPa [H. Sun et al., Nature (London) 621, 493 (2023)]. We analyze the pairing mechanism and pairing symmetry in a bilayer Hubbard model with two orbitals in the Eg multiplet. In the weak to moderate interaction regime, our functional renormalization group (FRG) calculations yield s +/--wave Cooper pairing triggered by leading spin fluctuations. The gap function changes sign across the Fermi pockets, and in real space the pairing is dominated by intra-unit-cell intraorbital components with antiphase between the on-site ones. In the strong-coupling limit, we develop a low-energy effective theory in terms of atomic one- and two-electron states in the Eg multiplet. The variational treatment of the effective theory produces results consistent with the FRG ones, suggesting the robustness of such a pairing function. The driving force for superconductivity in the strong-coupling limit can be attributed to the local pair-hopping term and the spin exchange on vertical bonds. We also discuss a possible scenario for the weak insulating behavior under low pressures in terms of the tendency toward the formation of charge order in the strong-coupling limit.
期刊
IF:
3.7
论文数:
15.4W
被引数:
41.0W
机构
引用论文
Finite-energy spin fluctuations as a pairing glue in systems with coexisting electron and hole bands
PHYSICAL REVIEW B
IF3.7
Unrestricted renormalized mean field theory of strongly correlated electron systems
PHYSICAL REVIEW B
IF3.7
Antiferromagnetically driven electronic correlations in iron pnictides and cuprates
PHYSICAL REVIEW B
IF3.7

