Abstract
Kagome metals with van Hove singularities near the Fermi level can host intriguing quantum phenomena such as chiral loop currents, electronic nematicity, and unconventional superconductivity. However, to our best knowledge, unconventional magnetic states driven by van Hove singularities–like spin-density waves–have not been observed experimentally in kagome metals. Here, we report the magnetic and electronic structure of the layered kagome metal CeTi3Bi4, where Ti kagome electronic structure interacts with a magnetic sublattice of Ce3+Jeff = 1/2 moments. Neutron diffraction reveals an incommensurate spin-density wave ground state of the Ce3+ moments, coexisting with commensurate antiferromagnetic order across most of the temperature-field phase diagram. The commensurate component is preferentially suppressed by thermal fluctuations and magnetic field, yielding a rich phase diagram involving an intermediate single-Q spin-density wave phase. First-principles calculations and angle-resolved photoemission spectroscopy identify van Hove singularities near the Fermi level, with the observed magnetic propagation vectors connecting their high density of states, strongly suggesting a van Hove singularity-assisted spin-density wave. These findings establish kagome metals LnTi3Bi4 as a model platform where the characteristic electronic structure of the kagome lattice plays a pivotal role in magnetic order.
| Original language | English |
|---|---|
| Article number | 4384 |
| Journal | Nature Communications |
| Volume | 16 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
We acknowledge O. Garlea for helpful discussions and thank Sung Kwan Mo for beamline assistance at the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to HB-1A on proposal number IPTS-32021.1 and WAND on Proposal No. IPTS-32078.1. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. M.N. acknowledges the support from the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-SC0024304 and the Air Force Office of Scientific Research MURI (Grant No. FA9550-20-1-0322). The TAS-2 experiment at JRR-3 was performed under the US\u2013Japan Cooperative Program on Neutron Scattering. This research used resources of the Advanced Light Source, a U.S. Department of Energy Office of Science User Facility, under Contract No. DE-AC02-05CH11231. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy Office of Science User Facility. Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( https://www.energy.gov/doe-public-access-plan ). We acknowledge O. Garlea for helpful discussions and thank Sung Kwan Mo for beamline assistance at the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to HB-1A on proposal number IPTS-32021.1 and WAND2 on Proposal No. IPTS-32078.1. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. M.N. acknowledges the support from the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-SC0024304 and the Air Force Office of Scientific Research MURI (Grant No. FA9550-20-1-0322). The TAS-2 experiment at JRR-3 was performed under the US\u2013Japan Cooperative Program on Neutron Scattering. This research used resources of the Advanced Light Source, a U.S. Department of Energy Office of Science User Facility, under Contract No. DE-AC02-05CH11231. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy Office of Science User Facility. Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (https://www.energy.gov/doe-public-access-plan).