Homecond-mat.str-elarXiv:2605.30074

Electronic Origin of Ferromagnetic Excitations in the Candidate Spin-Triplet Superconductor CeSb2

cond-mat.str-elcond-mat.supr-con2026-05v1license

Abstract

The origin of quasi-one-dimensional (q1D) ferromagnetic (FM) excitations in the candidate spin-triplet superconductor CeSb2_2 has remained unclear. Here we report an electronic mechanism for emergent q1D magnetism in the quasi-two-dimensional lattice of CeSb2_2, revealed by angle-resolved photoemission spectroscopy (ARPES). High-resolution ARPES resolves no spin-density-wave gap on the dispersive Fermi pockets, disfavoring a nesting-driven mechanism for the q1D FM excitations. Instead, resonant ARPES reveals a pronounced selective enhancement of Ce 4ff spectral weight on the C2C_2-distributed Fermi pockets aligned with the Ce ladder. This observation signifies band-selective Kondo coupling that generates strongly anisotropic magnetic exchange interactions, which can naturally account for both the q1D ferromagnetic excitations and the competing magnetic orders. Our results identify a band-selective Kondo coupling mechanism for emergent low-dimensional magnetism in correlated ff-electron systems.

Cite

@article{arxiv.2605.30074,
  title  = {Electronic Origin of Ferromagnetic Excitations in the Candidate Spin-Triplet Superconductor CeSb2},
  author = {Xiaoxiao Wang and Xiaoyang Chen and Suppanut Sangphet and Yifei Fang and Yilin Wang and Chihao Li and Minyinan Lei and Nan Guo and Yuanhe Song and Rui Peng and Haichao Xu and Donglai Feng},
  journal= {arXiv preprint arXiv:2605.30074},
  year   = {2026}
}