2025/02/28 by Yin, Yucong, Zhan, Jun, Liu, Boyang +1
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2502.21016
The recently discovered bilayer Ruddlesden-Popper nickelate La3Ni2O7 exhibits superconductivity with a remarkable transition temperature Tc≈ 80 K under applied pressures above 14.0 GPa. This discovery of new family of high-temperature superconductors has garnered significant attention in the condensed matter physics community. In this work, we assume the this high-temperature superconductor is mediated by phonons and investigate the pairing symmetry in two distinct models: (i) the full-coupling case, where the Ni-dx2-y2 and Ni-d3z2-r2 orbitals are treated equally in both interlayer and intralayer coupling interactions, and (ii) the half-coupling case, where the intralayer coupling involves only the dx2-y2 orbital, while the interlayer coupling is restricted to the d3z2-r2 orbital. Our calculations reveal that the interlayer coupling favors an s±-wave superconducting state, whereas the intralayer coupling promotes an s++-wave symmetry. Additionally, we discuss the implications of pair-hopping interactions on the superconducting properties. These findings provide valuable insights into the pairing mechanisms and symmetry of this newly discovered high-temperature superconductor.