Spin density wave and van Hove singularity in the kagome metal CeTiBi

Park, P.*; Ortiz, B. R.*; Spargue, M.*; Sakuya, A. P.*; Chen, S. A.*; Frontzek, M. D.*; Tian, W.*; Sibille, R.*; Mazzone, D. G.*; Tabata, Chihiro; Kaneko, Koji   ; Debeer-Schmitt, L. M.*; Stone, M. B.*; Parker, D. S.*; Samolyuk, G. D.*; Miao, H.*; Neupane, M.*; Christianson, A. D.*

Kagome metals with van Hove singularities (VHSs) near the Fermi level can host intriguing quantum phenomena, including chiral loop currents, electronic nematicity, and unconventional superconductivity. However, unconventional magnetic states driven by VHSs, such as spin-density waves (SDWs), have yet to be observed experimentally in kagome metals. Here, we present a comprehensive investigation of the magnetic and electronic structure of the layered kagome metal CeTiBi, where the Ti kagome electronic structure interacts with a magnetic sublattice of Ce = 1/2 moments. Our findings establish the rare-earth Kagome metals LnTi3Bi4 as a model platform where characteristic electronic structure of the kagome lattice plays a pivotal role in magnetic order.